Always fail when trying to store to an undeclared global variable, even if it was found.

src/ic.h

Index: src/ic.h
diff --git a/src/ic.h b/src/ic.h
index 784512a1c49f8b2f421495dc93cee5d1a1fafadb..04b0bb5a83a06962f788ea3e7347b364c0e3e542 100644
--- a/src/ic.h
+++ b/src/ic.h
@@ -110,16 +110,16 @@ class IC {
 
   // Returns if this IC is for contextual (no explicit receiver)
   // access to properties.
-  bool IsContextual(Handle<Object> receiver) {
+  bool IsUndeclaredGlobal(Handle<Object> receiver) {
     if (receiver->IsGlobalObject()) {
-      return SlowIsContextual();
+      return SlowIsUndeclaredGlobal();
     } else {
-      ASSERT(!SlowIsContextual());
+      ASSERT(!SlowIsUndeclaredGlobal());
       return false;
     }
   }
 
-  bool SlowIsContextual() {
+  bool SlowIsUndeclaredGlobal() {
     return ComputeMode() == RelocInfo::CODE_TARGET_CONTEXT;
   }