The generated code for the split fp128 load/stores was missing a small yet important adjustment to the pointer metadata being fed into `getStore` and `getLoad`, making it out of sync with the effective memory address.
This problem often resulted in instructions being scheduled in the wrong order.
I also took this chance to clean up some "wrong" uses of `getAlignment` as done in D77687.
Thanks @jrtc27 for finding the problem and providing a patch.
Patch by LemonBoy and Jessica Clarke(jrtc27)
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D94345
Craig Topper