Fix HCheckValue::Canonicalize wrt uninitialized HConstant unique.

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index a35134952da753ee932fd104ee680e06f5173d2f..1c6f76f3b157313e3a8490494b14a0c92926498a 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -1566,10 +1566,11 @@ void HCheckValue::PrintDataTo(StringStream* stream) {
 
 
 HValue* HCheckValue::Canonicalize() {
-  return (value()->IsConstant() &&
-          HConstant::cast(value())->GetUnique() == object_)
-      ? NULL
-      : this;
+  if (value()->IsConstant()) {
+    Unique<Object> unique = HConstant::cast(value())->GetUnique();

[titzer, 2014/03/03 12:42:38]

Can you move this logic into a method on HConstant instead, e.g. EqualsUnique()
?

+    if (unique.IsInitialized() && unique == object_) return NULL;
+  }
+  return this;
 }