Optimizing: ARM64 negated bitwise operations simplification

Use negated instructions on ARM64 to replace [bitwise operation + not]
patterns, that is:
a & ~b (BIC)
a | ~b (ORN)
a ^ ~b (EON)

The simplification only happens if the Not is only used by the bitwise
operation. It does not happen if both inputs are Not's (this should be
handled by a generic simplification applying De Morgan's laws).

Change-Id: I0e112b23fd8b8e10f09bfeff5994508a8ff96e9c
9 files changed