[llvm-branch-commits] [llvm-objcopy] Support CREL (PR #97521)

[Fangrui Song via llvm-branch-commits]

https://github.com/MaskRay created https://github.com/llvm/llvm-project/pull/97521

llvm-objcopy may modify the symbol table and need to rewrite
relocations. For CREL, while we can reuse the decoder from #91280, we
need an encoder to support CREL.

Since MC/ELFObjectWriter.cpp has an existing encoder, and MC is at a
lower layer than Object, extract the encoder to a new header file
llvm/MC/MCELFExtras.h.

Link: https://discourse.llvm.org/t/rfc-crel-a-compact-relocation-format-for-elf/77600