[BOLT][DWARF] Fix handling of GCed CU function

[ayermolo]

Summary

A CU can have only one function so CU will have low_pc/high_pc. If this funciton
is GCed by LLD low_pc will become 0x0, and BOLT can't map this to output. We
kind of were getting away with it in monolithic DWARF, but with split DWARF
there is only skeleton CU, so we end up with rnglist with header and array, but
no body. This caused LLDB to report an error.

[ayermolo]

removed some code that snuck in

[ayermolo]

fixed tests

bolt/lib/Rewrite/DWARFRewriter.cpp

case dwarf::DW_TAG_skeleton_unit: {
       auto ModuleRangesOrError = DIE.getAddressRanges();
       if (!ModuleRangesOrError) {
         consumeError(ModuleRangesOrError.takeError());
         break;
       }
       DWARFAddressRangesVector &ModuleRanges = *ModuleRangesOrError;
       DebugAddressRangesVector OutputRanges =
           BC.translateModuleAddressRanges(ModuleRanges);
+      std::optional<AttrInfo> LowPCAttrInfo =
+          findAttributeInfo(DIE, dwarf::DW_AT_low_pc);
+      // For a case where LLD GCs only function used in the CU.
+      // If CU doesn't have DW_AT_low_pc we are not going to convert,
+      // so don't need to do anything.
+      if (OutputRanges.empty() && !Unit.isDWOUnit() && LowPCAttrInfo)
+        OutputRanges.push_back({0, 0});
       const uint64_t RangesSectionOffset =
           RangesSectionWriter.addRanges(OutputRanges);
       if (!Unit.isDWOUnit())
         ARangesSectionWriter->addCURanges(Unit.getOffset(),
                                           std::move(OutputRanges));
       updateDWARFObjectAddressRanges(DIE, RangesSectionOffset, DebugInfoPatcher,
                                      AbbrevWriter, 0, RangesBase);
       break;

bolt/test/X86/Inputs/dwarf5-df-cu-function-gc-helper.s

+# int helper() {
+# return 1;
+# }
+
+  .text
+  .file "helper.cpp"
+  .section  .text._Z6helperv,"ax",@progbits
+  .globl  _Z6helperv                      # -- Begin function _Z6helperv
+  .p2align  4, 0x90
+  .type _Z6helperv,@function
+_Z6helperv:                             # @_Z6helperv
+.Lfunc_begin0:
+  .file 0 "." "helper.cpp" md5 0xf0d02b43e83785dc27fc4814c9d9262b
+  .loc  0 1 0                           # helper.cpp:1:0
+  .cfi_startproc
+# %bb.0:                                # %entry
+  pushq %rbp
+  .cfi_def_cfa_offset 16
+  .cfi_offset %rbp, -16
+  movq  %rsp, %rbp
+  .cfi_def_cfa_register %rbp
+.Ltmp0:
+  .loc  0 2 1 prologue_end              # helper.cpp:2:1
+  movl  $1, %eax
+  .loc  0 2 1 epilogue_begin is_stmt 0  # helper.cpp:2:1
+  popq  %rbp
+  .cfi_def_cfa %rsp, 8
+  retq
+.Ltmp1:
+.Lfunc_end0:
+  .size _Z6helperv, .Lfunc_end0-_Z6helperv
+  .cfi_endproc
+                                        # -- End function
+  .section  .debug_abbrev,"",@progbits
+  .byte 1                               # Abbreviation Code
+  .byte 74                              # DW_TAG_skeleton_unit
+  .byte 0                               # DW_CHILDREN_no
+  .byte 16                              # DW_AT_stmt_list
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 114                             # DW_AT_str_offsets_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 27                              # DW_AT_comp_dir
+  .byte 37                              # DW_FORM_strx1
+  .ascii  "\264B"                         # DW_AT_GNU_pubnames
+  .byte 25                              # DW_FORM_flag_present
+  .byte 118                             # DW_AT_dwo_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 115                             # DW_AT_addr_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 0                               # EOM(3)
+  .section  .debug_info,"",@progbits
+.Lcu_begin0:
+  .long .Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit
+.Ldebug_info_start0:
+  .short  5                               # DWARF version number
+  .byte 4                               # DWARF Unit Type
+  .byte 8                               # Address Size (in bytes)
+  .long .debug_abbrev                   # Offset Into Abbrev. Section
+  .quad -1286039323196723149
+  .byte 1                               # Abbrev [1] 0x14:0x14 DW_TAG_skeleton_unit
+  .long .Lline_table_start0             # DW_AT_stmt_list
+  .long .Lstr_offsets_base0             # DW_AT_str_offsets_base
+  .byte 0                               # DW_AT_comp_dir
+                                        # DW_AT_GNU_pubnames
+  .byte 1                               # DW_AT_dwo_name
+  .byte 0                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .long .Laddr_table_base0              # DW_AT_addr_base
+.Ldebug_info_end0:
+  .section  .debug_str_offsets,"",@progbits
+  .long 12                              # Length of String Offsets Set
+  .short  5
+  .short  0
+.Lstr_offsets_base0:
+  .section  .debug_str,"MS",@progbits,1
+.Lskel_string0:
+  .asciz  "." # string offset=0
+.Lskel_string1:
+  .asciz  "helper.dwo"                    # string offset=50
+  .section  .debug_str_offsets,"",@progbits
+  .long .Lskel_string0
+  .long .Lskel_string1
+  .section  .debug_str_offsets.dwo,"e",@progbits
+  .long 28                              # Length of String Offsets Set
+  .short  5
+  .short  0
+  .section  .debug_str.dwo,"eMS",@progbits,1
+.Linfo_string0:
+  .asciz  "_Z6helperv"                    # string offset=0
+.Linfo_string1:
+  .asciz  "helper"                        # string offset=11
+.Linfo_string2:
+  .asciz  "int"                           # string offset=18
+.Linfo_string3:
+  .asciz  "clang version 17.0.0 (https://github.com/llvm/llvm-project.git 640e07c49037cca41a1bfbeb916b569d8c950aea)" # string offset=22
+.Linfo_string4:
+  .asciz  "helper.cpp"                    # string offset=127
+.Linfo_string5:
+  .asciz  "helper.dwo"                    # string offset=138
+  .section  .debug_str_offsets.dwo,"e",@progbits
+  .long 0
+  .long 11
+  .long 18
+  .long 22
+  .long 127
+  .long 138
+  .section  .debug_info.dwo,"e",@progbits
+  .long .Ldebug_info_dwo_end0-.Ldebug_info_dwo_start0 # Length of Unit
+.Ldebug_info_dwo_start0:
+  .short  5                               # DWARF version number
+  .byte 5                               # DWARF Unit Type
+  .byte 8                               # Address Size (in bytes)
+  .long 0                               # Offset Into Abbrev. Section
+  .quad -1286039323196723149
+  .byte 1                               # Abbrev [1] 0x14:0x1b DW_TAG_compile_unit
+  .byte 3                               # DW_AT_producer
+  .short  33                              # DW_AT_language
+  .byte 4                               # DW_AT_name
+  .byte 5                               # DW_AT_dwo_name
+  .byte 2                               # Abbrev [2] 0x1a:0x10 DW_TAG_subprogram
+  .byte 0                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .byte 1                               # DW_AT_frame_base
+  .byte 86
+  .byte 0                               # DW_AT_linkage_name
+  .byte 1                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 1                               # DW_AT_decl_line
+  .long 42                              # DW_AT_type
+                                        # DW_AT_external
+  .byte 3                               # Abbrev [3] 0x2a:0x4 DW_TAG_base_type
+  .byte 2                               # DW_AT_name
+  .byte 5                               # DW_AT_encoding
+  .byte 4                               # DW_AT_byte_size
+  .byte 0                               # End Of Children Mark
+.Ldebug_info_dwo_end0:
+  .section  .debug_abbrev.dwo,"e",@progbits
+  .byte 1                               # Abbreviation Code
+  .byte 17                              # DW_TAG_compile_unit
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 37                              # DW_AT_producer
+  .byte 37                              # DW_FORM_strx1
+  .byte 19                              # DW_AT_language
+  .byte 5                               # DW_FORM_data2
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 118                             # DW_AT_dwo_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 2                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 0                               # DW_CHILDREN_no
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 64                              # DW_AT_frame_base
+  .byte 24                              # DW_FORM_exprloc
+  .byte 110                             # DW_AT_linkage_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 3                               # Abbreviation Code
+  .byte 36                              # DW_TAG_base_type
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 62                              # DW_AT_encoding
+  .byte 11                              # DW_FORM_data1
+  .byte 11                              # DW_AT_byte_size
+  .byte 11                              # DW_FORM_data1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 0                               # EOM(3)
+  .section  .debug_addr,"",@progbits
+  .long .Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution
+.Ldebug_addr_start0:
+  .short  5                               # DWARF version number
+  .byte 8                               # Address size
+  .byte 0                               # Segment selector size
+.Laddr_table_base0:
+  .quad .Lfunc_begin0
+.Ldebug_addr_end0:
+  .section  .debug_gnu_pubnames,"",@progbits
+  .long .LpubNames_end0-.LpubNames_start0 # Length of Public Names Info
+.LpubNames_start0:
+  .short  2                               # DWARF Version
+  .long .Lcu_begin0                     # Offset of Compilation Unit Info
+  .long 40                              # Compilation Unit Length
+  .long 26                              # DIE offset
+  .byte 48                              # Attributes: FUNCTION, EXTERNAL
+  .asciz  "helper"                        # External Name
+  .long 0                               # End Mark
+.LpubNames_end0:
+  .section  .debug_gnu_pubtypes,"",@progbits
+  .long .LpubTypes_end0-.LpubTypes_start0 # Length of Public Types Info
+.LpubTypes_start0:
+  .short  2                               # DWARF Version
+  .long .Lcu_begin0                     # Offset of Compilation Unit Info
+  .long 40                              # Compilation Unit Length
+  .long 42                              # DIE offset
+  .byte 144                             # Attributes: TYPE, STATIC
+  .asciz  "int"                           # External Name
+  .long 0                               # End Mark
+.LpubTypes_end0:
+  .ident  "clang version 17.0.0 (https://github.com/llvm/llvm-project.git 640e07c49037cca41a1bfbeb916b569d8c950aea)"
+  .section  ".note.GNU-stack","",@progbits
+  .addrsig
+  .section  .debug_line,"",@progbits
+.Lline_table_start0:

bolt/test/X86/Inputs/dwarf5-df-cu-function-gc-main.s

+# int main() {
+#   return 0;
+# }
+
+  .text
+  .file "main.cpp"
+  .section  .text.main,"ax",@progbits
+  .globl  main                            # -- Begin function main
+  .p2align  4, 0x90
+  .type main,@function
+main:                                   # @main
+.Lfunc_begin0:
+  .file 0 "." "main.cpp" md5 0xbb12fec8d002b1f0e06f7dee4604c6cc
+  .loc  0 1 0                           # main.cpp:1:0
+  .cfi_startproc
+# %bb.0:                                # %entry
+  pushq %rbp
+  .cfi_def_cfa_offset 16
+  .cfi_offset %rbp, -16
+  movq  %rsp, %rbp
+  .cfi_def_cfa_register %rbp
+  movl  $0, -4(%rbp)
+.Ltmp0:
+  .loc  0 2 3 prologue_end              # main.cpp:2:3
+  xorl  %eax, %eax
+  .loc  0 2 3 epilogue_begin is_stmt 0  # main.cpp:2:3
+  popq  %rbp
+  .cfi_def_cfa %rsp, 8
+  retq
+.Ltmp1:
+.Lfunc_end0:
+  .size main, .Lfunc_end0-main
+  .cfi_endproc
+                                        # -- End function
+  .section  .debug_abbrev,"",@progbits
+  .byte 1                               # Abbreviation Code
+  .byte 74                              # DW_TAG_skeleton_unit
+  .byte 0                               # DW_CHILDREN_no
+  .byte 16                              # DW_AT_stmt_list
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 114                             # DW_AT_str_offsets_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 27                              # DW_AT_comp_dir
+  .byte 37                              # DW_FORM_strx1
+  .ascii  "\264B"                         # DW_AT_GNU_pubnames
+  .byte 25                              # DW_FORM_flag_present
+  .byte 118                             # DW_AT_dwo_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 115                             # DW_AT_addr_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 0                               # EOM(3)
+  .section  .debug_info,"",@progbits
+.Lcu_begin0:
+  .long .Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit
+.Ldebug_info_start0:
+  .short  5                               # DWARF version number
+  .byte 4                               # DWARF Unit Type
+  .byte 8                               # Address Size (in bytes)
+  .long .debug_abbrev                   # Offset Into Abbrev. Section
+  .quad 6318074710904753300
+  .byte 1                               # Abbrev [1] 0x14:0x14 DW_TAG_skeleton_unit
+  .long .Lline_table_start0             # DW_AT_stmt_list
+  .long .Lstr_offsets_base0             # DW_AT_str_offsets_base
+  .byte 0                               # DW_AT_comp_dir
+                                        # DW_AT_GNU_pubnames
+  .byte 1                               # DW_AT_dwo_name
+  .byte 0                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .long .Laddr_table_base0              # DW_AT_addr_base
+.Ldebug_info_end0:
+  .section  .debug_str_offsets,"",@progbits
+  .long 12                              # Length of String Offsets Set
+  .short  5
+  .short  0
+.Lstr_offsets_base0:
+  .section  .debug_str,"MS",@progbits,1
+.Lskel_string0:
+  .asciz  "." # string offset=0
+.Lskel_string1:
+  .asciz  "main.dwo"                      # string offset=50
+  .section  .debug_str_offsets,"",@progbits
+  .long .Lskel_string0
+  .long .Lskel_string1
+  .section  .debug_str_offsets.dwo,"e",@progbits
+  .long 24                              # Length of String Offsets Set
+  .short  5
+  .short  0
+  .section  .debug_str.dwo,"eMS",@progbits,1
+.Linfo_string0:
+  .asciz  "main"                          # string offset=0
+.Linfo_string1:
+  .asciz  "int"                           # string offset=5
+.Linfo_string2:
+  .asciz  "clang version 17.0.0 (https://github.com/llvm/llvm-project.git 640e07c49037cca41a1bfbeb916b569d8c950aea)" # string offset=9
+.Linfo_string3:
+  .asciz  "main.cpp"                      # string offset=114
+.Linfo_string4:
+  .asciz  "main.dwo"                      # string offset=123
+  .section  .debug_str_offsets.dwo,"e",@progbits
+  .long 0
+  .long 5
+  .long 9
+  .long 114
+  .long 123
+  .section  .debug_info.dwo,"e",@progbits
+  .long .Ldebug_info_dwo_end0-.Ldebug_info_dwo_start0 # Length of Unit
+.Ldebug_info_dwo_start0:
+  .short  5                               # DWARF version number
+  .byte 5                               # DWARF Unit Type
+  .byte 8                               # Address Size (in bytes)
+  .long 0                               # Offset Into Abbrev. Section
+  .quad 6318074710904753300
+  .byte 1                               # Abbrev [1] 0x14:0x1a DW_TAG_compile_unit
+  .byte 2                               # DW_AT_producer
+  .short  33                              # DW_AT_language
+  .byte 3                               # DW_AT_name
+  .byte 4                               # DW_AT_dwo_name
+  .byte 2                               # Abbrev [2] 0x1a:0xf DW_TAG_subprogram
+  .byte 0                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .byte 1                               # DW_AT_frame_base
+  .byte 86
+  .byte 0                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 1                               # DW_AT_decl_line
+  .long 41                              # DW_AT_type
+                                        # DW_AT_external
+  .byte 3                               # Abbrev [3] 0x29:0x4 DW_TAG_base_type
+  .byte 1                               # DW_AT_name
+  .byte 5                               # DW_AT_encoding
+  .byte 4                               # DW_AT_byte_size
+  .byte 0                               # End Of Children Mark
+.Ldebug_info_dwo_end0:
+  .section  .debug_abbrev.dwo,"e",@progbits
+  .byte 1                               # Abbreviation Code
+  .byte 17                              # DW_TAG_compile_unit
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 37                              # DW_AT_producer
+  .byte 37                              # DW_FORM_strx1
+  .byte 19                              # DW_AT_language
+  .byte 5                               # DW_FORM_data2
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 118                             # DW_AT_dwo_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 2                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 0                               # DW_CHILDREN_no
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 64                              # DW_AT_frame_base
+  .byte 24                              # DW_FORM_exprloc
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 3                               # Abbreviation Code
+  .byte 36                              # DW_TAG_base_type
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 62                              # DW_AT_encoding
+  .byte 11                              # DW_FORM_data1
+  .byte 11                              # DW_AT_byte_size
+  .byte 11                              # DW_FORM_data1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 0                               # EOM(3)
+  .section  .debug_addr,"",@progbits
+  .long .Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution
+.Ldebug_addr_start0:
+  .short  5                               # DWARF version number
+  .byte 8                               # Address size
+  .byte 0                               # Segment selector size
+.Laddr_table_base0:
+  .quad .Lfunc_begin0
+.Ldebug_addr_end0:
+  .section  .debug_gnu_pubnames,"",@progbits
+  .long .LpubNames_end0-.LpubNames_start0 # Length of Public Names Info
+.LpubNames_start0:
+  .short  2                               # DWARF Version
+  .long .Lcu_begin0                     # Offset of Compilation Unit Info
+  .long 40                              # Compilation Unit Length
+  .long 26                              # DIE offset
+  .byte 48                              # Attributes: FUNCTION, EXTERNAL
+  .asciz  "main"                          # External Name
+  .long 0                               # End Mark
+.LpubNames_end0:
+  .section  .debug_gnu_pubtypes,"",@progbits
+  .long .LpubTypes_end0-.LpubTypes_start0 # Length of Public Types Info
+.LpubTypes_start0:
+  .short  2                               # DWARF Version
+  .long .Lcu_begin0                     # Offset of Compilation Unit Info
+  .long 40                              # Compilation Unit Length
+  .long 41                              # DIE offset
+  .byte 144                             # Attributes: TYPE, STATIC
+  .asciz  "int"                           # External Name
+  .long 0                               # End Mark
+.LpubTypes_end0:
+  .ident  "clang version 17.0.0 (https://github.com/llvm/llvm-project.git 640e07c49037cca41a1bfbeb916b569d8c950aea)"
+  .section  ".note.GNU-stack","",@progbits
+  .addrsig
+  .section  .debug_line,"",@progbits
+.Lline_table_start0:

bolt/test/X86/dwarf5-df-cu-function-gc.test

+# REQUIRES: system-linux
+; RUN: rm -rf %t
+; RUN: mkdir %t
+; RUN: cd %t
+; RUN: llvm-mc --split-dwarf-file=main.dwo --triple=x86_64-unknown-linux-gnu \
+; RUN: --filetype=obj %p/Inputs/dwarf5-df-cu-function-gc-main.s -o=main.o
+; RUN: llvm-mc --split-dwarf-file=helper.dwo --triple=x86_64-unknown-linux-gnu \
+; RUN: --filetype=obj %p/Inputs/dwarf5-df-cu-function-gc-helper.s -o=helper.o
+; RUN: %clang %cflags -gdwarf-5 -gsplit-dwarf=split -Wl,--entry=main -Wl,--gc-sections main.o helper.o -o main.exe
+; RUN: llvm-bolt main.exe -o main.exe.bolt --update-debug-sections
+; RUN: llvm-dwarfdump --debug-addr main.exe.bolt > addr.txt
+; RUN: llvm-dwarfdump --show-form --verbose --debug-info main.exe.bolt >> addr.txt
+; RUN: cat addr.txt | FileCheck -check-prefix=BOLT %s
+
+; Tests we generate range when linker GCs only function used in CU
+
+; BOLT: Addrs:
+; BOLT-NEXT: 0x[[#%.16x,ADDR:]]
+; BOLT: Addrs:
+; BOLT-NEXT: 0x[[#%.16x,ADDR1:]]
+
+; BOLT: DW_TAG_skeleton_unit
+; BOLT: DW_AT_ranges [DW_FORM_rnglistx] (indexed (0x0) rangelist = 0x00000010
+; BOLT-NEXT: [0x[[#ADDR]], 0x[[#ADDR + 0xf]]))
+; BOLT: DW_TAG_skeleton_unit
+; BOLT: DW_AT_ranges [DW_FORM_rnglistx] (indexed (0x0) rangelist = 0x00000024
+; BOLT-NEXT: [0x[[#ADDR1]], 0x[[#ADDR1]]))