Fix for potential issue related to replacing CheckMaps with values.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 3fb867bde3d5ed6403c6ee474a2e5dca71469d1c..a0f6c22ed991495e7e6981790916dcae247698a0 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -3915,7 +3915,13 @@ void HGraph::RestoreActualValues() {
 
     for (HInstructionIterator it(block); !it.Done(); it.Advance()) {
       HInstruction* instruction = it.Current();
-      if (instruction->ActualValue() != instruction) {
+      if (instruction->CheckFlag(HValue::kIsDead)) {
+        // The instruction was marked as deleted but left in the graph
+        // as a control flow dependency point for subsequent
+        // instructions.
+        instruction->DeleteAndReplaceWith(instruction->ActualValue());

[titzer, 2014/01/23 18:34:46]

Not sure this is safe for every kind of instruction. Probably only want to
DeleteAndReplaceWith() when ActualValue() != this, i.e. below.

[Igor Sheludko, 2014/01/28 17:45:05]

Done.

+
+      } else if (instruction->ActualValue() != instruction) {
         ASSERT(instruction->IsInformativeDefinition());
         if (instruction->IsPurelyInformativeDefinition()) {
           instruction->DeleteAndReplaceWith(instruction->RedefinedOperand());