Add a "nohle" byte code to skip an instruction pattern

Add a "nohle" byte code to skip an instruction pattern

The a2/a3 mem_offs MOV opcodes are invalid with XRELEASE; those
instructions instead have to use a modrm form.  Therefore give a way
to annotate those instruction patters so the pattern matcher will move
on to the next pattern, rather than selecting them and then issue a
warning.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>