This hook it is trying to tell, even without aliasing information, that two MIs access different memory addresses. This function returns true if two MIs access different memory addresses and false otherwise.
After implemented this hook, we will model the memory dependency in the scheduling dependency graph more precise, and will have more opportunity to reorder the load/stores, as they didn't have the dependency at some condition.
There is no perf impact for spec2017 with this patch.