[exceptions] use `exc.toString()` instead of a `exc.message` in `exc.details()`

std/haxe/CallStack.hx

@@ -133,7 +133,7 @@ abstract CallStack(Array<StackItem>) from Array<StackItem> {
 
 	static function exceptionToString(e:Exception):String {
 		if(e.previous == null) {
-			return 'Exception: ${e.message}${e.stack}';
+			return 'Exception: ${e.toString()}${e.stack}';
 		}
 		var result = '';
 		var e:Null<Exception> = e;