Rework external function handlers (#4599)

Instead of a fixed number of arguments, a call info structure is passed
to the handlers, which can be extended in the future without breaknig the
API. This structure holds new.target value, so its getter function is removed.

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

jerry-ext/handler/handler-print.c

@@ -37,13 +37,11 @@
  *         error - otherwise.
  */
 jerry_value_t
-jerryx_handler_print (const jerry_value_t func_obj_val, /**< function object */
-                      const jerry_value_t this_p, /**< this arg */
+jerryx_handler_print (const jerry_call_info_t *call_info_p, /**< call information */
                       const jerry_value_t args_p[], /**< function arguments */
                       const jerry_length_t args_cnt) /**< number of function arguments */
 {
-  (void) func_obj_val; /* unused */
-  (void) this_p; /* unused */
+  (void) call_info_p; /* unused */
 
   const char * const null_str = "\\u0000";