[Isolates] Merge crankshaft (r5922 from bleeding_edge).

src/math.js

Index: src/math.js
diff --git a/src/math.js b/src/math.js
index 90667d76cf90206aaf20b87908a395d059650473..fa1934da41503b45ff67d29f5b7ad6110845f3c3 100644
--- a/src/math.js
+++ b/src/math.js
@@ -258,6 +258,14 @@ function SetupMath() {
     "max", MathMax,
     "min", MathMin
   ));
+
+  // The values here are from the MathFunctionId enum in objects.h.
+  %SetMathFunctionId($Math.floor, 1);
+  %SetMathFunctionId($Math.round, 2);
+  %SetMathFunctionId($Math.abs, 4);
+  %SetMathFunctionId($Math.sqrt, 0xd);
+  // TODO(erikcorry): Set the id of the other functions so they can be
+  // optimized.
 };