ARM: enable decoding of pc-relative PLD/PLI

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184701 91177308-0d34-0410-b5e6-96231b3b80d8
ARM: fix IT decoding

mask == 0 -> UNPRED

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184702 91177308-0d34-0410-b5e6-96231b3b80d8
ARM: fix thumb1 nop decoding

In thumb1, NOP is a pseudo-instruction equivalent to mov r8, r8.
However the disassembler should not use this alias.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184703 91177308-0d34-0410-b5e6-96231b3b80d8