Fix the .arch asm parser to use the full set of features for the architecture
and any extensions on the command line. Add and update testcases accordingly
as well as add an extension that was used but not supported.
llvm-svn: 280971
Add support to the AArch64 IAS for the `.arch` directive. This allows the
assembly input to use architectural functionality in part of a file. This is
used in existing code like BoringSSL.
Resolves PR26016!
llvm-svn: 272241
Eric Christopher