Remove instructions properly (stack check elimination was leaving "dangling uses" around).

src/hydrogen-instructions.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 772 matching lines @@
   // Verify that instructions that may have side-effects are followed
   // by a simulate instruction.
   if (HasObservableSideEffects() && !IsOsrEntry()) {
     ASSERT(next()->IsSimulate());
   }
 
   // Verify that instructions that can be eliminated by GVN have overridden
   // HValue::DataEquals.  The default implementation is UNREACHABLE.  We
   // don't actually care whether DataEquals returns true or false here.
   if (CheckFlag(kUseGVN)) DataEquals(this);
+
+  // Verify that all uses are in the graph.
+  for (HUseIterator use = uses(); !use.Done(); use.Advance()) {
+    if (use.value()->IsInstruction()) {
+      ASSERT(HInstruction::cast(use.value())->IsLinked());
+    }
+  }
 }
 #endif
 
 
 void HDummyUse::PrintDataTo(StringStream* stream) {
   value()->PrintNameTo(stream);
 }
 
 
 void HUnaryCall::PrintDataTo(StringStream* stream) {
@@ skipping 2131 matching lines @@
 
 
 void HCheckFunction::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 #endif
 
 } }  // namespace v8::internal