[clang] Pass more flags to ld64.lld

* ld64.lld now completely supports -export_dynamic (D119372), so map -rdynamic
  to -export_dynamic like already done for ld64

* ld64.lld has been supporting -object_path_lto for well over a year (D92537),
  so pass it like already done for ld64

Differential Revision: https://reviews.llvm.org/D119612