Add support for new.target (#3469)

Notable changes:
* Extracted the pure JS/builtin and external C method invocations
  into two new methods (`ecma_op_function_call_{simple, external}`).
* Updated parser/scanner to handle "new.target" correctly.
* Added JS test case.

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

jerry-core/vm/vm.h

@@ -261,6 +261,7 @@ typedef enum
   VM_OC_RETURN_PROMISE,          /**< return from an async function */
   VM_OC_STRING_CONCAT,           /**< string concatenation */
   VM_OC_GET_TEMPLATE_OBJECT,     /**< GetTemplateObject operation */
+  VM_OC_PUSH_NEW_TARGET,         /**< push new.target onto the stack */
 #endif /* ENABLED (JERRY_ES2015) */
   VM_OC_NONE,                    /**< a special opcode for unsupported byte codes */
 } vm_oc_types;
@@ -317,6 +318,7 @@ typedef enum
   VM_OC_RETURN_PROMISE = VM_OC_NONE,          /**< return from an async function */
   VM_OC_STRING_CONCAT = VM_OC_NONE,           /**< string concatenation */
   VM_OC_GET_TEMPLATE_OBJECT = VM_OC_NONE,     /**< GetTemplateObject operation */
+  VM_OC_PUSH_NEW_TARGET = VM_OC_NONE,         /**< push new.target onto the stack */
 #endif /* !ENABLED (JERRY_ES2015) */
 
   VM_OC_UNUSED = VM_OC_NONE                   /**< placeholder if the list is empty */