Fix invalid DCHECK for movzx/movsx.

k86Movzx8RM and kMovsx8RM don't have to use eax/ecx/edx/ebx.
The incorrect check could fail for LoadBaseDisp() with
kUnsignedByte or kSignedByte.

Change-Id: I777f14cf372c7b211ad8c595d4a8a47533bdd0fc
1 file changed