[turbofan] Optimized lowering of DYNAMIC_LOCAL lookup slot loads.

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 fbd5c214223f86fcf3e5cded82ca3e822796909e..e6743b3f65b16915775832669b9601945fb58708 100644
--- a/src/compiler/js-typed-lowering.h
+++ b/src/compiler/js-typed-lowering.h
@@ -46,6 +46,7 @@ class JSTypedLowering final : public AdvancedReducer {
   Reduction ReduceJSLoadContext(Node* node);
   Reduction ReduceJSStoreContext(Node* node);
   Reduction ReduceJSLoadDynamicGlobal(Node* node);
+  Reduction ReduceJSLoadDynamicContext(Node* node);
   Reduction ReduceJSEqual(Node* node, bool invert);
   Reduction ReduceJSStrictEqual(Node* node, bool invert);
   Reduction ReduceJSUnaryNot(Node* node);