[demangler PATCH]: Revert and update generic lambda demangling

[demangler PATCH]: Revert and update generic lambda demangling

https://gcc.gnu.org/ml/gcc-patches/2017-09/msg01482.html
	PR demangler/82195
	* cp-demangle.c (d_name): Revert addition of 'toplevel' parm.
	(has_return_type): Recurse for DEMANGLE_COMPONENT_LOCAL_NAME.
	(d_encoding): Revert d_name change.  Use is_fnqual_component_type
	to strip modifiers that do not belong.
	(d_special_name, d_class_enum_type): Revert d_name call change.
	(d_expresion_1): Commonize DEMANGLE_COMPONENT_UNARY building.
	(d_local_name): Revert parsing of a function type.
	(d_print_comp_inner): An inner LOCAL_NAME might contain a
	TEMPLATE.
	* testsuite/demangle-expected: Add & adjust tests

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@253075 138bc75d-0d04-0410-961f-82ee72b054a4