When decoding VEX prefixed instructions, the x86 predecoder wasn't walking past the opcode byte and so was also interpreting it as the modRM byte. Reported-by: likunxi@fas.harvard.edu Change-Id: I6d4bdabfa03411704c48d905c50c7b23072fc615 Reviewed-on: https://gem5-review.googlesource.com/5281 Reviewed-by: Gabe Black <gabeblack@google.com> Maintainer: Gabe Black <gabeblack@google.com>