Add R0, SP and FP to reserved registers so that register allocator wont
use them.
Remove printing CloseParenthesis after operand
Fixed IsSpecialRegister().
Fix stack grow direction so that eliminateFrameIndex() would work.

Also added debug logs so that debugging further issues would be easy.
Remove unused getStackPointerBias()
Fix isLoadFromStackSlot() and isStoreFromStackSlot()

I feeling sleepy now and dont feel confident about these functions
so adding an assert to catch it later.