Fix x86 inline ams 'q' constraint support. In 32-bit mode, it's just like 'Q',...

Fix x86 inline ams 'q' constraint support. In 32-bit mode, it's just like 'Q', i.e. EAX, EDX, ECX, EBX. In 64-bit mode, it just means all the i64r registers. Yeah, that makes sense.

llvm-svn: 76248