Added toBeNaN matcher

src/core/Matchers.js

@@ -150,6 +150,17 @@ jasmine.Matchers.prototype.toBeNull = function() {
   return (this.actual === null);
 };
 
+/**
+ * Matcher that compares the actual to NaN.
+ */
+jasmine.Matchers.prototype.toBeNaN = function() {
+	this.message = function() {
+		return [ "Expected " + jasmine.pp(this.actual) + " to be NaN." ];
+	};
+
+	return (this.actual !== this.actual);
+};
+
 /**
  * Matcher that boolean not-nots the actual.
  */