Refactor to ensure function name match exists.

Previously, the function would error for several examples, e.g. `constructorName( inheritedPropertyDescriptors( [] ) )`.

Author: Planeshifter

lib/node_modules/@stdlib/utils/constructor-name/lib/main.js

@@ -54,6 +54,7 @@ var isBuffer = require( '@stdlib/assert/is-buffer' );
 * // returns 'Function'
 */
 function constructorName( v ) {
+	var match;
 	var name;
 	var ctor;
 	name = nativeClass( v ).slice( 8, -1 );
@@ -62,7 +63,10 @@ function constructorName( v ) {
 		if ( typeof ctor.name === 'string' ) {
 			return ctor.name;
 		}
-		return RE.exec( ctor.toString() )[ 1 ];
+		match = RE.exec( ctor.toString() );
+		if ( match ) {
+			return match[ 1 ];
+		}
 	}
 	if ( isBuffer( v ) ) {
 		return 'Buffer';