Better codegen for '<expression> === void <literal>'.

src/full-codegen.h

Index: src/full-codegen.h
diff --git a/src/full-codegen.h b/src/full-codegen.h
index 87951ebffce478f8e391b2bebe7a6cc329aa1010..44e1816ebdcb81597d73805e21d0006eac4c6671 100644
--- a/src/full-codegen.h
+++ b/src/full-codegen.h
@@ -369,6 +369,21 @@ class FullCodeGenerator: public AstVisitor {
                          Label* if_false,
                          Label* fall_through);
 
+  // Platform-specific code for comparing the type of a value with
+  // a given literal string.
+  void EmitLiteralCompareTypeof(Expression* expr,
+                                Handle<String> check,
+                                Label* if_true,
+                                Label* if_false,
+                                Label* fall_through);
+
+  // Platform-specific code for strict equality comparison with
+  // the undefined value.
+  void EmitLiteralCompareUndefined(Expression* expr,
+                                   Label* if_true,
+                                   Label* if_false,
+                                   Label* fall_through);
+
   // Bailout support.
   void PrepareForBailout(Expression* node, State state);
   void PrepareForBailoutForId(int id, State state);