Create specialized code stubs for PixelArray loads.

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 9feced2f94b24ec9fb8a792ebe7d21e1ca84c9a4..8d0d6de7c6d96d001c287f275fa85ca0486e15f2 100644
--- a/src/x64/code-stubs-x64.h
+++ b/src/x64/code-stubs-x64.h
@@ -447,6 +447,18 @@ class NumberToStringStub: public CodeStub {
 };
 
 
+// Loads a indexed element from a pixel array.
+void GenerateFastPixelArrayLoad(MacroAssembler* masm,
+                                Register receiver,
+                                Register key,
+                                Register elements,
+                                Register untagged_key,
+                                Register result,
+                                Label* not_pixel_array,
+                                Label* key_not_smi,
+                                Label* out_of_range);
+
+
 } }  // namespace v8::internal
 
 #endif  // V8_X64_CODE_STUBS_X64_H_