[llvm-readobj][yaml2obj] Support SHT_LLVM_SYMPART, SHT_LLVM_PART_EHDR and SHT_LLVM_PART_PHDR

[MaskRay]

Summary

See http://lists.llvm.org/pipermail/llvm-dev/2019-February/130583.html
and D60242 for the lld partition feature.

This patch:

• Teaches yaml2obj to parse the 3 section types.
• Teaches llvm-readobj/llvm-readelf to dump the 3 section types.

There is no test for SHT_LLVM_DEPENDENT_LIBRARIES in llvm-readobj. Add
it as well.

lib/Object/ELF.cpp

switch (Type) {
     STRINGIFY_ENUM_CASE(ELF, SHT_ANDROID_RELA);
     STRINGIFY_ENUM_CASE(ELF, SHT_ANDROID_RELR);
     STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_ODRTAB);
     STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_LINKER_OPTIONS);
     STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_CALL_GRAPH_PROFILE);
     STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_ADDRSIG);
     STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_DEPENDENT_LIBRARIES);
     STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_SYMPART);
+    STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_PART_EHDR);
+    STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_PART_PHDR);
     STRINGIFY_ENUM_CASE(ELF, SHT_GNU_ATTRIBUTES);
     STRINGIFY_ENUM_CASE(ELF, SHT_GNU_HASH);
     STRINGIFY_ENUM_CASE(ELF, SHT_GNU_verdef);
     STRINGIFY_ENUM_CASE(ELF, SHT_GNU_verneed);
     STRINGIFY_ENUM_CASE(ELF, SHT_GNU_versym);
   default:
     return "Unknown";
   }

lib/ObjectYAML/ELFYAML.cpp

#define ECase(X) IO.enumCase(Value, #X, ELF::X)
   ECase(SHT_ANDROID_REL);
   ECase(SHT_ANDROID_RELA);
   ECase(SHT_ANDROID_RELR);
   ECase(SHT_LLVM_ODRTAB);
   ECase(SHT_LLVM_LINKER_OPTIONS);
   ECase(SHT_LLVM_CALL_GRAPH_PROFILE);
   ECase(SHT_LLVM_ADDRSIG);
   ECase(SHT_LLVM_DEPENDENT_LIBRARIES);
+  ECase(SHT_LLVM_SYMPART);
+  ECase(SHT_LLVM_PART_EHDR);
+  ECase(SHT_LLVM_PART_PHDR);
   ECase(SHT_GNU_ATTRIBUTES);
   ECase(SHT_GNU_HASH);
   ECase(SHT_GNU_verdef);
   ECase(SHT_GNU_verneed);
   ECase(SHT_GNU_versym);
   switch (Object->Header.Machine) {
   case ELF::EM_ARM:
     ECase(SHT_ARM_EXIDX);

test/tools/llvm-readobj/elf-section-types.test

 # LLVM: Name: llvm_odrtab
 # LLVM: Type: SHT_LLVM_ODRTAB
 # LLVM: Name: linker_options
 # LLVM: Type: SHT_LLVM_LINKER_OPTIONS
 # LLVM: Name: llvm_call_graph_profile
 # LLVM: Type: SHT_LLVM_CALL_GRAPH_PROFILE
 # LLVM: Name: llvm_addrsig
 # LLVM: Type: SHT_LLVM_ADDRSIG
+# LLVM: Name: .deplibs
+# LLVM: Type: SHT_LLVM_DEPENDENT_LIBRARIES
+# LLVM: Name: .llvm_sympart.f
+# LLVM: Type: SHT_LLVM_SYMPART
+# LLVM: Name: part1
+# LLVM: Type: SHT_LLVM_PART_EHDR
+# LLVM: Name: .phdrs
+# LLVM: Type: SHT_LLVM_PART_PHDR
 # LLVM: Name: gnu_attributes
 # LLVM: Type: SHT_GNU_ATTRIBUTES
 # LLVM: Name: gnu_hash
 # LLVM: Type: SHT_GNU_HASH
 # LLVM: Name: gnu_verdef
 # LLVM: Type: SHT_GNU_verdef
 # LLVM: Name: gnu_verneed
 # LLVM: Type: SHT_GNU_verneed

 # GNU-NEXT: relr                    RELR
 # GNU-NEXT: android_rel             ANDROID_REL
 # GNU-NEXT: android_rela            ANDROID_RELA
 # GNU-NEXT: android_relr            RELR
 # GNU-NEXT: llvm_odrtab             LLVM_ODRTAB
 # GNU-NEXT: linker_options          LLVM_LINKER_OPTIONS
 # GNU-NEXT: llvm_call_graph_profile LLVM_CALL_GRAPH_PROFILE
 # GNU-NEXT: llvm_addrsig            LLVM_ADDRSIG
+# GNU-NEXT: .deplibs                LLVM_DEPENDENT_LIBRARIES
+# GNU-NEXT: .llvm_sympart.f         LLVM_SYMPART
+# GNU-NEXT: part1                   LLVM_PART_EHDR
+# GNU-NEXT: .phdrs                  LLVM_PART_PHDR
 # GNU-NEXT: gnu_attributes          ATTRIBUTES
 # GNU-NEXT: gnu_hash                GNU_HASH
 # GNU-NEXT: gnu_verdef              VERDEF
 # GNU-NEXT: gnu_verneed             VERNEED
 # GNU-NEXT: unknown                 0x1000: <unknown>
 # GNU-NEXT: loos                    LOOS+0x0
 # GNU-NEXT: fooos                   LOOS+0xF00
 # GNU-NEXT: hios                    VERSYM
Sections:
   - Name: llvm_odrtab
     Type: SHT_LLVM_ODRTAB
   - Name: linker_options
     Type: SHT_LLVM_LINKER_OPTIONS
   - Name: llvm_call_graph_profile
     Type: SHT_LLVM_CALL_GRAPH_PROFILE
   - Name: llvm_addrsig
     Type: SHT_LLVM_ADDRSIG
+  - Name: .deplibs
+    Type: SHT_LLVM_DEPENDENT_LIBRARIES
+  - Name: .llvm_sympart.f
+    Type: SHT_LLVM_SYMPART
+  - Name: part1
+    Type: SHT_LLVM_PART_EHDR
+  - Name: .phdrs
+    Type: SHT_LLVM_PART_PHDR
   - Name: gnu_attributes
     Type: SHT_GNU_ATTRIBUTES
   - Name: gnu_hash
     Type: SHT_GNU_HASH
   - Name: gnu_verdef
     Type: SHT_GNU_verdef
     Info: 0
     Entries:

tools/llvm-readobj/ELFDumper.cpp

static std::string getSectionTypeString(unsigned Arch, unsigned Type) {
   case SHT_LLVM_LINKER_OPTIONS:
     return "LLVM_LINKER_OPTIONS";
   case SHT_LLVM_CALL_GRAPH_PROFILE:
     return "LLVM_CALL_GRAPH_PROFILE";
   case SHT_LLVM_ADDRSIG:
     return "LLVM_ADDRSIG";
   case SHT_LLVM_DEPENDENT_LIBRARIES:
     return "LLVM_DEPENDENT_LIBRARIES";
+  case SHT_LLVM_SYMPART:
+    return "LLVM_SYMPART";
+  case SHT_LLVM_PART_EHDR:
+    return "LLVM_PART_EHDR";
+  case SHT_LLVM_PART_PHDR:
+    return "LLVM_PART_PHDR";
   // FIXME: Parse processor specific GNU attributes
   case SHT_GNU_ATTRIBUTES:
     return "ATTRIBUTES";
   case SHT_GNU_HASH:
     return "GNU_HASH";
   case SHT_GNU_verdef:
     return "VERDEF";
   case SHT_GNU_verneed: