gdb/ChangeLog:

	PR python/18285
	* NEWS: Document new gdb.XMethodWorker.get_result_type method.
	* eval.c (evaluate_subexp_standard) <OP_FUNCALL>: Handle
	EVAL_AVOID_SIDE_EFFECTS for xmethods.
	* extension-priv.h (struct extension_language_ops)
	<get_xmethod_result_type>: New member.
	* extension.c (get_xmethod_result_type): New function.
	* extension.h (get_xmethod_result_type): Declare.
	* python/py-xmethods.c (get_result_type_method_name): New static
	global.
	(py_get_result_type_method_name): Ditto.
	(gdbpy_get_xmethod_result_type): New function.
	(gdbpy_initialize_xmethods): Initialize py_get_result_type_method_name.
	* python/python-internal.h (gdbpy_get_xmethod_result_type): Declare.
	* python/python.c (python_extension_ops): Add
	gdbpy_get_xmethod_result_type.
	* python/lib/gdb/xmethod.py (XMethodWorker): Add get_result_type.
	* valarith.c (value_x_binop): Handle EVAL_AVOID_SIDE_EFFECTS for
	xmethods.
	(value_x_unop): Ditto.
	* value.c (result_type_of_xmethod): New function.
	* value.h (result_type_of_xmethod): Declare.

gdb/testsuite/ChangeLog:

	* gdb.python/py-xmethods.exp: Add ptype tests.
	* gdb.python/py-xmethods.py (E_method_char_worker): Add
	get_result_type method.

gdb/doc/ChangeLog:

	* python.texi (Xmethod API) <gdb.XMethodWorker.get_result_type>:
	Document.
	(Writing an Xmethod): Add get_result_type to example.