Assert: Add alias for throws called 'raises'

Brings back the original method name, for compatibility with environments
that consider 'throws' a reserved word.

Fixes qunitjs#663

src/assert.js

@@ -197,3 +197,10 @@ QUnit.assert = Assert.prototype = {
 		}
 	}
 };
+
+// Provide an alternative to assert.throws(), for enviroments that consider throws a reserved word
+// Known to us are: Closure Compiler, Narwhal
+(function() {
+	/*jshint sub:true */
+	Assert.prototype.raises = Assert.prototype[ "throws" ];
+}());

test/assert.js

@@ -230,3 +230,10 @@ QUnit.test( "throws", function( assert ) {
 		"handle string typed thrown errors"
 	);
 });
+
+QUnit.test( "raises, alias for throws", function( assert ) {
+	assert.expect( 1 );
+	assert.raises(function() {
+		throw "my error";
+	});
+});