masks to match inversely for the code as is to work. For the example given
we actually want:
bfi r0, r2, #1, #1
not #0, however, given the way the pattern is written it's not possible
at the moment.
Fixes rdar://9177502
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128320 91177308-0d34-0410-b5e6-96231b3b80d8
