[NFC][ELF] Don't reimplement addReloc in GotSection::addConstant
This is just a copy of InputSectionBase::addReloc, so we can just
forward to that rather than poking into the internals. Whilst here, move
the implementation to the header so it can be inlined.
This is helpful downstream for CHERI, as static relocations to emit an
entire capability (whether for a relative relocation or for an undefined
weak symbol) need to be split in two, one per word, as getRelocTargetVA
only returns a uint64_t. Having a single function that pushes to
InputSectionBase's static relocations array centralises that so the
outside world can pretend it's a singular relocation, and internally it
gets mapped to the pair.
Reviewers: MaskRay
Reviewed By: MaskRay
Pull Request: https://github.com/llvm/llvm-project/pull/171177