[lldb] Support arm64e in the expression evaluator (#186001)
This PR upstreams support for PtrAuth in the LLDB expression evaluator.
It's a rebased version of an older patch in the Swiftlang repo
(https://github.com/swiftlang/llvm-project/pull/5012) but adapted to not
rely on `GlobalPtrAuthInfo.h`. I followed Anton's advice, and instead of
iterating over all globals and hack on wrappers, the pass now iterates
over all global uses and fixes up ConstantPtrAuth expressions if any.
This is one of the last large chunks of downstream PtrAuth code in LLDB,
and the primary blocker for running the LLDB test suite in arm64e mode
on Apple Silicon, which I'd really like to make the default in the
future.
llvm-project
4f298d4e - [lldb] Support arm64e in the expression evaluator (#186001)
