Thumb2 assembly parsing and encoding for LDR pre-indexed w/ writeback.

Adjust encoding of writeback load/store instructions to better reflect the
way the operand types are represented.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139270 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed