Add failing test for exporting a global.

test/function/export-global/_config.js

@@ -0,0 +1,9 @@
+var assert = require( 'assert' );
+
+module.exports = {
+	description: 'any global variables in scope can be re-exported',
+
+	exports: function ( exports ) {
+		assert.equal( exports.Buffer, Buffer );
+	}
+};

test/function/export-global/main.js

@@ -0,0 +1 @@
+export { Buffer };