Introduce C API to query the type of an Error object (#2177)

New api function:
* jerry_get_error_type

Additionally update a few places where this new function
can be used.

JerryScript-DCO-1.0-Signed-off-by: Peter Gal pgal.u-szeged@partner.samsung.com

jerry-core/include/jerryscript-core.h

@@ -64,6 +64,8 @@ typedef enum
  */
 typedef enum
 {
+  JERRY_ERROR_NONE = 0,  /**< No Error */
+
   JERRY_ERROR_COMMON,    /**< Error */
   JERRY_ERROR_EVAL,      /**< EvalError */
   JERRY_ERROR_RANGE,     /**< RangeError */
@@ -299,6 +301,11 @@ void jerry_value_set_error_flag (jerry_value_t *value_p);
 void jerry_value_set_abort_flag (jerry_value_t *value_p);
 jerry_value_t jerry_get_value_without_error_flag (jerry_value_t value);
 
+/**
+ * Error object function(s).
+ */
+jerry_error_t jerry_get_error_type (const jerry_value_t value);
+
 /**
  * Getter functions of 'jerry_value_t'.
  */