[llvm] [BOLT][RISCV]Fix handling of GOT relocation pairs (PR #149658)

[via llvm-commits]

dinyy wrote:

@aaupov could you review my code?
I remove the change that moving instruction.
This patch only about dealing with GOT relocation.  
Specific Steps:
1. keeping imm when disassemble (only instruction with GOT relocation and PCREL_LO12) .
2. for instruction with GOT relocation find the correct pair , and change Relocation.value to get the correct __BOLT_got_zero + offset

This patch has been verified on mysql-8.0. And change on [reloc-got.s](https://github.com/llvm/llvm-project/pull/149658/files#diff-fe33ded758321d1887e97073715517bcf6d9f55a9f87f41445a67102160637d1) could help .


https://github.com/llvm/llvm-project/pull/149658