ART: Fix Quick's DCE+GVN

DCE_GVN does not take into account the following case:
  mov a, b
  mov c, b
when optimization tries to replace a with c it must ensure that
for all uses of a there is no new definition of c before use.
Otherwise that use will incorrectly substituted with new c instead
of original b.

Bug: 23102860
Change-Id: I48ee0bd4386419b0f9c814c21b3537a392518cd1
Signed-off-by: Serguei Katkov <>
2 files changed