Add a quick test to $.support for native bind.

As per the suggestion by ajpiano: 9f8cd6c499 (commitcomment-218658)

src/core.js

@@ -751,7 +751,7 @@ jQuery.extend({
 			return undefined;
 		}
 
-		if ( jQuery.isFunction( Function.prototype.bind ) ) {
+		if ( jQuery.support.nativeBind ) {
 			// Native bind
 			args = slice.call( arguments, 1 );
 			proxy = Function.prototype.bind.apply( fn, args );

src/support.js

@@ -60,6 +60,9 @@
 		// (WebKit defaults to false instead of true, IE too, if it's in an optgroup)
 		optSelected: opt.selected,
 
+		// Test for native Function#bind.
+		nativeBind: jQuery.isFunction( Function.prototype.bind ),
+
 		// Will be defined later
 		deleteExpando: true,
 		optDisabled: false,