OptimizeLoadsAfterStores only dropped a load right after a store of the same
reg. Now a load of anything the block stored or loaded before becomes a reg
move (with the extension for 8/16-bit loads), as long as nothing in between
may have changed the memory, the address reg, or the reg holding the value.
Only a store through the same base at a disjoint range is known not to alias,
and constant addresses outside RAM are left alone.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
