quickjs_compat.h: Added a compat macro for Js_IsError for quickjs-ng

Since 57fffbbb6a98b316e5195ff31655cd13db2bfa5b ("Remove unused JSContext
argument from JS_IsError")[1], QuickJS-NG's JS_IsError() takes only the
value parameter, no context.

[1]: quickjs-ng/quickjs@57fffbb

Signed-off-by: Zurab Kvachadze <zurabid2016@gmail.com>

Author: BalkanMadman

src/quickjs_compat.h

@@ -22,3 +22,7 @@
 #ifndef JS_BOOL
     #define JS_BOOL bool
 #endif
+
+#ifdef QUICKJS_NG
+    #define JS_IsError(cx, val) JS_IsError(val)
+#endif