[RTDYLD] support absolute relocations where needed

These appear in some sections, such as DWARF tables, since
RuntimeDyldELF explicitly maps to this as a sentinel value:
https://github.com/llvm/llvm-project/blob/29d1fba7b5335d969e3e5daa84b7a25cd1fa75ef/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp#L1199

That could then be a source of problems if it tried to examine these
sections (for example, with either setProcessAllSections(true) or ORCv2 on i686).

Replaces https://reviews.llvm.org/D89241

Reviewed By: lhames, vchuravy

Differential Revision: https://reviews.llvm.org/D90722

(cherry picked from commit 85f4be09)