[BOLT] Support input binaries that use R_X86_GOTPC64 #68036
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In large code model, the address of GOT is calculated by the static linker via R_X86_GOTPC64 reloc applied against a MOVABSQ instruction. In the final binary, it can be disassembled as a regular immediate, but because such immediate is the result of PC-relative pointer arithmetic, we need to parse this relocation and update this calculation whenever we move code, otherwise we break the code trying to read GOT. A test case showing how GOT is accessed was provided. Differential Revision: https://reviews.llvm.org/D158911
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In large code model, the address of GOT is calculated by the static linker via R_X86_GOTPC64 reloc applied against a MOVABSQ instruction. In the final binary, it can be disassembled as a regular immediate, but because such immediate is the result of PC-relative pointer arithmetic, we need to parse this relocation and update this calculation whenever we move code, otherwise we break the code trying to read GOT.
A test case showing how GOT is accessed was provided.
Differential Revision: https://reviews.llvm.org/D158911