Revert "JIT: Use rsb and shift in easy multiply."

This reverts commit 7913c4af8efa04ab5563840181e516129735e755.
Revert "JIT: Combine add with shift."

This reverts commit a47bf41dd7429f8b3800dafbca32b36d25bbbbf2.
Revert "JIT: Hoist loop load operations above loop."

This reverts commit 0706b74bc079365c9d5af203c23686cc8c6ed6ff.

Conflicts:
	vm/compiler/Loop.h