Speed up two unit tests to avoid timeouts and make tests finish faster.

test/mjsunit/array-join.js

Index: test/mjsunit/array-join.js
===================================================================
--- test/mjsunit/array-join.js	(revision 10596)
+++ test/mjsunit/array-join.js	(working copy)
@@ -75,10 +75,10 @@
   Array.prototype.toString = oldToString;
 }
 
-var a = new Array(123123123);
-assertEquals(123123122, String(a).length);
-assertEquals(123123122, a.join(",").length);
-assertEquals(246246244, a.join("oo").length);
+var a = new Array(123123);
+assertEquals(123122, String(a).length);
+assertEquals(123122, a.join(",").length);
+assertEquals(246244, a.join("oo").length);
 
 a = new Array(Math.pow(2,32) - 1);  // Max length.
 assertEquals("", a.join(""));
@@ -90,4 +90,4 @@
 for (var i = 0; i < a.length; i++) a[i] = undefined;
 a[5] = "ab";
 a[90000] = "cd";
-assertEquals("abcd", a.join(""));  // Must not throw.
+assertEquals("abcd", a.join(""));  // Must not throw.