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/es6/generators-runtime.js b/test/mjsunit/es6/generators-runtime.js
index 98015b7..5c426b2 100644
--- a/test/mjsunit/es6/generators-runtime.js
+++ b/test/mjsunit/es6/generators-runtime.js
@@ -99,7 +99,7 @@
   assertSame(GeneratorObjectPrototype,
              Object.getPrototypeOf((function*(){yield 1}).prototype));
 
-  var expected_property_names = ["next", "throw", "constructor"];
+  var expected_property_names = ["next", "return", "throw", "constructor"];
   var found_property_names =
       Object.getOwnPropertyNames(GeneratorObjectPrototype);