[llvm] [JITLink] Support AArch64 big-endian (BE8) ELF objects (PR #225120)

[dong jianqiang via llvm-commits]

dongjianqiang2 wrote:

@lhames Thanks! I've pushed an update that follows the PPC64 pattern: EM_AARCH64 now dispatches on the ELF data encoding in ELF.cpp, and both entry points are thin wrappers over a single template <llvm::endianness> implementation, so BE objects go through the same ELFT-templated graph builder as LE.

For coverage, I replaced the single BE test with ELF_relocations_be.s – a big-endian port of ELF_relocations.s covering the full relocation set – and added ELF_ehframe_be.s for eh-frame processing on big-endian data. 

https://github.com/llvm/llvm-project/pull/225120