[LICM] Refactoring + Improvements + Exclusivity Support

Major refactoring + tuning of LICM. Includes:
Support for hosting more array semantic calls
Remove restrictions for sinking instructions
Add support for hoisting and sinking instruction pairs (begin and end accesses)

Testing with Exclusivity enabled on a couple of benchmarks shows:
ReversedArray 7x improvement
StringWalk 2.6x improvement

Author: Joe Shajrawi