[llvm] 224502 - ARM: improve instruction validation for thumb mode

[Asiri Rathnayake]

Hi Saleem,

This patch:
http://llvm.org/viewvc/llvm-project?view=revision&revision=224502

Is crashing some MCHammer runs. Here's an llvm-mc reproducer:

> echo 'PUSH.W   {r0}' | ./bin/llvm-mc -triple=thumbv7 --show-encoding
--show-inst

Can you have a look?

Best,

- Asiri