[BOLT] Add GNUPropertyRewriter and warn on AArch64 BTI note (#161206)
This commit adds the GNUPropertyRewriter, which parses features from the
.note.gnu.property section.
Currently we only read the bit indicating BTI support
(GNU_PROPERTY_AARCH64_FEATURE_1_BTI).
As BOLT does not add BTI landing pads to targets of indirect
branches/calls, we have to emit a warning that the output binary may be
corrupted.