Cleanup of mjsunit.js code and make assertEquals more strict.

test/mjsunit/regress/regress-176.js

Index: test/mjsunit/regress/regress-176.js
diff --git a/test/mjsunit/regress/regress-176.js b/test/mjsunit/regress/regress-176.js
index b2048124687a7fe58b4d8f2907ca9e5a2f9d1a7f..ef0c4f11d40b50b590e5f78a95fdee8e6674f50d 100644
--- a/test/mjsunit/regress/regress-176.js
+++ b/test/mjsunit/regress/regress-176.js
@@ -27,24 +27,24 @@
 
 // See http://code.google.com/p/v8/issues/detail?id=176
 
-assertEquals("f,",
-             "foo".match(/(?:(?=(f)o))?f/).toString(),
-             "zero length match in (?:) with capture in lookahead");
-assertEquals("f,",
-             "foo".match(/(?=(f)o)?f/).toString(),
-             "zero length match in (?=) with capture in lookahead");
-assertEquals("fo,f",
-             "foo".match(/(?:(?=(f)o)f)?o/),
-             "non-zero length match with capture in lookahead");
-assertEquals("fo,f",
-             "foo".match(/(?:(?=(f)o)f?)?o/),
-             "non-zero length match with greedy ? in (?:)");
-assertEquals("fo,f",
-             "foo".match(/(?:(?=(f)o)f??)?o/),
-             "non-zero length match with non-greedy ? in (?:), o forces backtrack");
-assertEquals("fo,f",
-             "foo".match(/(?:(?=(f)o)f??)?./),
-             "non-zero length match with non-greedy ? in (?:), zero length match causes backtrack");
-assertEquals("f,",
-             "foo".match(/(?:(?=(f)o)fx)?./),
-             "x causes backtrack inside (?:)");
+assertArrayEquals(["f", undefined],
+                  "foo".match(/(?:(?=(f)o))?f/),
+                  "zero length match in (?:) with capture in lookahead");
+assertArrayEquals(["f", undefined],
+                  "foo".match(/(?=(f)o)?f/),
+                  "zero length match in (?=) with capture in lookahead");
+assertArrayEquals(["fo", "f"],
+                  "foo".match(/(?:(?=(f)o)f)?o/),
+                  "non-zero length match with capture in lookahead");
+assertArrayEquals(["fo", "f"],
+                  "foo".match(/(?:(?=(f)o)f?)?o/),
+                  "non-zero length match with greedy ? in (?:)");
+assertArrayEquals(["fo", "f"],
+                  "foo".match(/(?:(?=(f)o)f??)?o/),
+                  "non-zero length match with non-greedy ? in (?:), o forces backtrack");
+assertArrayEquals(["fo", "f"],
+                  "foo".match(/(?:(?=(f)o)f??)?./),
+                  "non-zero length match with non-greedy ? in (?:), zero length match causes backtrack");
+assertArrayEquals(["f", undefined],
+                  "foo".match(/(?:(?=(f)o)fx)?./),
+                  "x causes backtrack inside (?:)");