[llvm] [bolt][aarch64] Add R_AARCH64_P32_ABS16/32 relocations (PR #143773)

[Paschalis Mpeis via llvm-commits]

https://github.com/paschalis-mpeis commented:

Hey Alexei,

Thanks for the patch! The code itself looks okay. When trying @aaupov patch #132114 (currently marked as **draft**), I do get a failure on `AArch64/jump-table-info.s` as @whubeibei reports on issue #143709. 

After cherry-picking this PR on top of Amir's draft PR I get an assertion:
```
BinarySection.cpp:136: void llvm::bolt::BinarySection::emitAsData(MCStreamer &, const Twine &) const
: Assertion `SectionOffset <= SectionContents.size() && "overflow error"' failed.
```

Not sure if I missed something.

---

Regarding the relocations themselves, they appear to be part of the [ILP32](https://github.com/ARM-software/abi-aa/blob/main/aaelf64/aaelf64.rst#ilp32-beta) which is **Beta**. @yavtuk , @whubeibei could you share more details on how you get to generate those relocations in the input binary?

cc @smithp35 who can provide additional context around the status of ILP32.

https://github.com/llvm/llvm-project/pull/143773