Thumb2 assembly parsing for mul.w in IT block fix.

When the 3rd operand is not a low-register, and the first two operands are
the same low register, the parser was incorrectly trying to use the 16-bit
instruction encoding.

rdar://10449281

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144679 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed