Bitpatterns rejected by the decoder method of `MSR (immediate)` should be decoded as the `extended MSR (register)` instruction. Differential Revision: http://reviews.llvm.org/D7174 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242276 91177308-0d34-0410-b5e6-96231b3b80d8