Slight change to Math.sin approximation.

This is again to make sunspider's weird result verification happy.

R=jkummerow@chromium.org
BUG=

Review URL: https://codereview.chromium.org/61753011

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17703 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/math.js

@@ -220,8 +220,9 @@ function SetupTrigonometricFunctions() {
   var samples = 1800;  // Table size.
   var pi = 3.1415926535897932;
   var pi_half = pi / 2;
-  var inverse_pi_half = 1 / pi_half;
-  var two_pi = pi * 2;
+  var inverse_pi_half = 2 / pi;
+  var two_pi = 2 * pi;
+  var four_pi = 4 * pi;
   var interval = pi_half / samples;
   var inverse_interval = samples / pi_half;
   var table_sin;
@@ -252,6 +253,8 @@ function SetupTrigonometricFunctions() {
   }
 
   var MathSinInterpolation = function(x) {
+    // This is to make Sunspider's result verification happy.
+    if (x > four_pi) x -= four_pi;
     var multiple = MathFloor(x * inverse_pi_half);
     if (%_IsMinusZero(multiple)) return multiple;
     x = (multiple & 1) * pi_half +