The purpose of the patch is to fix the syntax of ARM mrc and mrc2 instructions when they are used to write to the APSR. In this case, the destination operand should be APSR_nzcv, and the encoding of the target should be 0b1111 (same as for PC). In pre-UAL syntax, this form used the PC register as a textual target. This is still allowed for backward compatibility.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181705 91177308-0d34-0410-b5e6-96231b3b80d8