[X86] Add coverage for 16-bit and 64-bit versions of bsf/bsr/bt/btc/btr/bts in...

[X86] Add coverage for 16-bit and 64-bit versions of bsf/bsr/bt/btc/btr/bts in the assembly tests that are supposed to provide full coverage. Add coverage for cwtl/cltq/cwtd/cqto as well.

llvm-svn: 356420