[JITLink][ELF/AARCH64][NFC] Add a testcase for R_AARCH64_ABS64

[sunho]

Summary

Add jitlink-check test cases for R_AARCH64_ABS64 relocation type.

[sgraenitz]

If it's not too much effort, can we abandon review and add it to the one with the implementation in D126658? You tracked the dependencies here in Phabricator nicely, but it's usually easier for people to see their relation in the git history if it's one commit. All functional changes need testing and so checking them in together is good practice. Thanks!

llvm/test/ExecutionEngine/JITLink/AArch64/ELF_aarch64_relocations.s

 # RUN: rm -rf %t && mkdir -p %t
 # RUN: llvm-mc -triple=aarch64-unknown-linux-gnu -relax-relocations=false -position-independent -filetype=obj -o %t/elf_reloc.o %s
-# RUN: llvm-jitlink -noexec -check %s %t/elf_reloc.o
+# RUN: llvm-jitlink -noexec \
+# RUN:              -check %s %t/elf_reloc.o
 
         .text
 
         .globl  main
         .p2align  2
         .type main,@function
 main:
         ret
test_str_32bit:
         str  w0, [x1, :lo12:named_data]
         .size test_str_32bit, .-test_str_32bit
 
         .globl  test_str_64bit
 test_str_64bit:
         str  x0, [x1, :lo12:named_data]
         .size test_str_64bit, .-test_str_64bit
 
+# Check R_AARCH64_ABS64 relocation of a function pointer to local symbol
+#
+# jitlink-check: *{8}local_func_addr_quad = named_func
+        .globl  local_func_addr_quad
+        .p2align  4
+local_func_addr_quad:
+        .xword  named_func
+        .size local_func_addr_quad, 8
+
         .globl  named_data
         .p2align  4
         .type   named_data,@object
 named_data:
         .quad   0x2222222222222222
         .quad   0x3333333333333333
         .size   named_data, .-named_data
+
+        .globl  named_func
+        .type named_func,@function
+named_func:
+        ret
+        .size   named_func, .-named_func