[llvm] Fix most LLVM_ABI annotations in MC/MCA (#202930)
This updates most LLVM_ABI annotations in the MC/MCA headers to match
expected usage:
* All public APIs should be properly annotated.
* Inlined functions should not be annotated.
These changes were done by a script fixing annotations on LLVM public
headers and manually checked.
This effort is tracked in #109483.
