Revert "Revert "Upgrade to 5.0.71.48"" DO NOT MERGE

This reverts commit f2e3994fa5148cc3d9946666f0b0596290192b0e,
and updates the x64 makefile properly so it doesn't break that
build.

FPIIM-449

Change-Id: Ib83e35bfbae6af627451c926a9650ec57c045605
(cherry picked from commit 109988c7ccb6f3fd1a58574fa3dfb88beaef6632)
diff --git a/test/mjsunit/harmony/simd.js b/test/mjsunit/harmony/simd.js
index 6330ac8..ff81506 100644
--- a/test/mjsunit/harmony/simd.js
+++ b/test/mjsunit/harmony/simd.js
@@ -407,7 +407,7 @@
   var simdFn = SIMD[type];
   var instance = createInstance(type);
   var sameValue = Object.is
-  var sameValueZero = natives.ImportNow("SameValueZero");
+  var sameValueZero = function(x, y) { return %SameValueZero(x, y); }
 
   // SIMD values should not be the same as instances of different types.
   checkTypeMatrix(type, function(other) {