Take loop side-effects into account when collecting side-effects on the path between two blocks.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 6c33609d1476e3177be0b4fa981273f02127f5b7..05d460970e44897f7f91e1ffed5b8b69f8752e1b 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -1503,6 +1503,9 @@ int HGlobalValueNumberer::CollectSideEffectsOnPathsToDominatedBlock(
         block->block_id() < dominated->block_id() &&
         visited_on_paths_.Add(block->block_id())) {
       side_effects |= block_side_effects_[block->block_id()];
+      if (block->IsLoopHeader()) {
+        side_effects |= loop_side_effects_[block->block_id()];
+      }
       side_effects |= CollectSideEffectsOnPathsToDominatedBlock(
           dominator, block);
     }