[clang] [llvm] [PAC][ELF][AArch64] Support signed personality function pointer (PR #113148)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-aarch64-darwin` running on `doug-worker-5` while building `clang,llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/190/builds/11048

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: CodeGen/AArch64/ptrauth-sign-personality.ll' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 1: /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc -mtriple=aarch64-linux -filetype=asm /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/CodeGen/AArch64/ptrauth-sign-personality.ll -o - | /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/CodeGen/AArch64/ptrauth-sign-personality.ll
+ /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/llc -mtriple=aarch64-linux -filetype=asm /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/CodeGen/AArch64/ptrauth-sign-personality.ll -o -
+ /Users/buildbot/buildbot-root/aarch64-darwin/build/bin/FileCheck /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/CodeGen/AArch64/ptrauth-sign-personality.ll
/Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/CodeGen/AArch64/ptrauth-sign-personality.ll:30:15: error: CHECK-NEXT: expected string not found in input
; CHECK-NEXT: .xword __gxx_personality_v0 at AUTH(ia,32429,addr)
              ^
<stdin>:68:29: note: scanning from here
DW.ref.__gxx_personality_v0:
                            ^
<stdin>:69:2: note: possible intended match here
 .xword __gxx_personality_v0
 ^

Input file: <stdin>
Check file: /Users/buildbot/buildbot-root/aarch64-darwin/llvm-project/llvm/test/CodeGen/AArch64/ptrauth-sign-personality.ll

-dump-input=help explains the following input dump.

Input was:
<<<<<<
           1:  .text 
           2:  .file "ptrauth-sign-personality.ll" 
           3:  .globl main // -- Begin function main 
           4:  .p2align 2 
           5:  .type main, at function 
           6: main: // @main 
           7: .Lfunc_begin0: 
           8:  .cfi_startproc 
           9:  .cfi_personality 156, DW.ref.__gxx_personality_v0 
          10:  .cfi_lsda 28, .Lexception0 
          11: // %bb.0: // %entry 
          12:  str x30, [sp, #-16]! // 8-byte Folded Spill 
          13:  .cfi_def_cfa_offset 16 
          14:  .cfi_offset w30, -16 
          15: .Ltmp0: 
          16:  bl foo 
          17: .Ltmp1: 
          18: .LBB0_1: // %common.ret 
          19:  mov w0, wzr 
          20:  ldr x30, [sp], #16 // 8-byte Folded Reload 
          21:  ret 
          22: .LBB0_2: // %lpad 
          23: .Ltmp2: 
          24:  b .LBB0_1 
          25: .Lfunc_end0: 
...

```

</details>

https://github.com/llvm/llvm-project/pull/113148