Following D109516, this patch re-uses the new helper function for ELF relocation traversal in the x86-64 backend.
The patch aims to be NFC (except debug output format). Please ping me if I introduced a functional change by accident.
This causes a warning when I do a release build with clang 10.0.0:
ELF_x86_64.cpp:308:13: warning: enumeration value 'PCRel32TLV' not handled in switch [-Wswitch]
Looks like a bad merge with https://reviews.llvm.org/D109293 (thanks @bkramer for pointing this out). I'll send a fix