Restore partial LSE.

This fixes a bug where we were using the wrong value for initializing an
allocation that we moved. See this test:
https://android-review.googlesource.com/c/platform/art/+/1825138/4/test/828-partial-lse/src/Main.java

Run LSE twice: one for the classical load store eliminiation, one for
moving allocations.

Test: test.py
Bug: 197981962
Change-Id: If317e10e239488876180047040dba66ae3fc8d4c
5 files changed