Faster string equals in generated code.

src/x64/code-stubs-x64.h

Index: src/x64/code-stubs-x64.h
diff --git a/src/x64/code-stubs-x64.h b/src/x64/code-stubs-x64.h
index 5398452e09614df64acdaa155eafd0752becad55..0ee10b5f4b3dc172ee891ed61e7e764c6b3fa3e8 100644
--- a/src/x64/code-stubs-x64.h
+++ b/src/x64/code-stubs-x64.h
@@ -364,10 +364,9 @@ class SubStringStub: public CodeStub {
 
 class StringCompareStub: public CodeStub {
  public:
-  explicit StringCompareStub() {}
+  StringCompareStub() {}
 
-  // Compare two flat ascii strings and returns result in rax after popping two
-  // arguments from the stack.
+  // Compares two flat ASCII strings and returns result in rax.
   static void GenerateCompareFlatAsciiStrings(MacroAssembler* masm,
                                               Register left,
                                               Register right,
@@ -376,6 +375,14 @@ class StringCompareStub: public CodeStub {
                                               Register scratch3,
                                               Register scratch4);
 
+  // Compares two flat ASCII strings for equality and returns result
+  // in rax.
+  static void GenerateFlatAsciiStringEquals(MacroAssembler* masm,
+                                            Register left,
+                                            Register right,
+                                            Register scratch1,
+                                            Register scratch2);
+
  private:
   Major MajorKey() { return StringCompare; }
   int MinorKey() { return 0; }