[LV] Complete load groups and release store groups. Try 2.

This is a complete fix for CompleteLoadGroups introduced in
D154309. We need to check for dependency between A and every member of
the load Group of B.
This patch also fixes another miscompile seen when we incorrectly sink stores
below a depending load (see testcase in
interleaved-accesses-sink-store-across-load.ll). This is fixed by
releasing store groups correctly.

This change was previously reverted (e85fd3cb) due to Asan failure with
use-after-free error. A testcase is added and the bug is fixed in this
version of the patch.

Differential Revision: https://reviews.llvm.org/D155520