[ORC][ORC-RT] Revert MachO TLV patches while I investigate more bot failures.

This reverts commit d4abdefc ("[ORC-RT] Rename
macho_tlv.x86-64.s to macho_tlv.x86-64.S (uppercase suffix)", and
a7733e95 ("Re-apply "[ORC][ORC-RT] Add initial
native-TLV support to MachOPlatform."), while I investigate failures on
ccache builders (e.g. https://lab.llvm.org/buildbot/#/builders/109/builds/18981)