4f53cc1dad
Add an addend field to reloc_external, and use it to move the responsibility for accounting for the difference between the end of an instruction (where the PC is considered to be in PC-relative on intel) and the beginning of the immediate field into the encoding code. Specifically, this makes IntelGOTPCRel4 directly correspond to R_X86_64_GOTPCREL, instead of also carrying an implicit `- 4`.