[turbofan] Move global constant optimization to AstGraphBuilder.

src/compiler/js-typed-lowering.h

Index: src/compiler/js-typed-lowering.h
diff --git a/src/compiler/js-typed-lowering.h b/src/compiler/js-typed-lowering.h
index 71f940798cd728f56f47bc7ec36b40d7eb06e847..dd6470c7379b0ca68f7d5c872353206c4cc3f2bc 100644
--- a/src/compiler/js-typed-lowering.h
+++ b/src/compiler/js-typed-lowering.h
@@ -41,7 +41,6 @@ class JSTypedLowering final : public AdvancedReducer {
   Reduction ReduceJSBitwiseOr(Node* node);
   Reduction ReduceJSMultiply(Node* node);
   Reduction ReduceJSComparison(Node* node);
-  Reduction ReduceJSLoadGlobal(Node* node);
   Reduction ReduceJSLoadNamed(Node* node);
   Reduction ReduceJSLoadProperty(Node* node);
   Reduction ReduceJSStoreProperty(Node* node);