Optimize a couple of common patterns involving conditional moves where the false

value is zero. Instead of a cmov + op, issue an conditional op instead. e.g.
    cmp   r9, r4
    mov   r4, #0
    moveq r4, #1 
    orr   lr, lr, r4

should be:
    cmp   r9, r4
    orreq lr, lr, #1

That is, optimize (or x, (cmov 0, y, cond)) to (or.cond x, y). Similarly extend
this to xor as well as (and x, (cmov -1, y, cond)) => (and.cond x, y).

It's possible to extend this to ADD and SUB but I don't think they are common.

rdar://8659097

llvm-svn: 151224