Move the shift operator and special value (32 encoded as 0 for PKHTB) handling
into the instruction printer. This cleans up a bit of the disassembler
special casing for these instructions, more easily handles not printing the
operand at all for "lsl #0" and prepares for correct asm parsing of these
operands.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135626 91177308-0d34-0410-b5e6-96231b3b80d8
