Add support for global variable references in toplevel code. We use...

test/mjsunit/compiler/globals.js

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 24 matching lines @@
 
 // Test that patching the IC in the compiled code works.
 assertEquals(1, eval('g = 1'));
 assertEquals(1, g);
 assertEquals(1, eval('g = 1'));
 assertEquals(1, g);
 
 // Test a second store.
 assertEquals("2", eval('g = "2"'));
 assertEquals("2", g);
+
+// Test a load.
+assertEquals("2", eval('g'));
+
+// Test that patching the IC in the compiled code works.
+assertEquals("2", eval('g'));
+assertEquals("2", eval('g'));
+
+// Test a second load.
+g = 3;
+assertEquals(3, eval('g'));