llvm: [ELF] Support some absolute/PC-relative relocation types for REL format

[alfredo]

Summary

Support R_PPC_REL32 to fix "ld.lld: error: drti.c:(.SUNW_dof+0x4E4): internal linker error: cannot read addend for relocation R_PPC_REL32" while building perl5.32 for powerpc. Also add some common relocation types for AArch64, PPC, and PPC64.

The patch was taken from https://reviews.llvm.org/D120535 and from LLVM15 to LLVM13 with trivial changes. The issue is a blocker for the upcoming 13.1-RELEASE.

Original patch commited: https://reviews.llvm.org/rG767e64fc11d7734843ec5bb0bd3f7330541bb1a6

If you think it's too risky we can restrict the change to powerpc only.

Test Plan

Build packages on 14-RELEASE and 13-STABLE using the patched in-tree compiler.

[fbsd-phab_maskray.me]

You may cherry pick https://github.com/llvm/llvm-project/commit/53fc5d9b9a0110f097c6e9f7aa3bff3621eaf268 to avoid the local changes.

[alfredo]

Abandoned due to https://cgit.freebsd.org/src/commit/?id=298c3e8d6b6405cbea13a7a1a1fbc1ad5a45c378

Thank you, @dim !