[X86][MC] Add R_X86_64_CODE_4_GOTTPOFF (#116633)

[X86][MC] Add R_X86_64_CODE_4_GOTTPOFF (#116633)

For

  mov name@GOTTPOFF(%rip), %reg
  add name@GOTTPOFF(%rip), %reg

add

  `R_X86_64_CODE_4_GOTTPOFF` = 44

if the instruction starts at 4 bytes before the relocation offset. It's
similar to R_X86_64_GOTTPOFF.

Linker can treat `R_X86_64_CODE_4_GOTTPOFF` as `R_X86_64_GOTTPOFF` or
convert the instructions above to

  mov $name@tpoff, %reg
  add $name@tpoff, %reg

if the first byte of the instruction at the relocation `offset - 4` is
`0xd5` (namely, encoded w/REX2 prefix) when possible.

Binutils patch:
https://github.com/bminor/binutils-gdb/commit/a533c8df598b5ef99c54a13e2b137c98b34b043c
Binutils mailthread:
https://sourceware.org/pipermail/binutils/2023-December/131463.html
ABI discussion:
https://groups.google.com/g/x86-64-abi/c/ACwD-UQXVDs/m/vrgTenKyFwAJ
Blog: https://kanrobert.github.io/rfc/All-about-APX-relocation