c++/coroutines: check for members we use in handle_types [PR105475]

Currently, it is possible to ICE GCC by giving it sufficiently broken
code, where sufficiently broken means a std::coroutine_handle missing a
default on the promise_type template argument, and missing members.
As the code generator relies on lookups in the coroutine_handle never
failing (and has no way to signal that error), lets do it ahead of time,
save the result, and use that.  This saves us some lookups and allows us
to propagate an error.

PR c++/105475 - coroutines: ICE in coerce_template_parms, at cp/pt.cc:9183

gcc/cp/ChangeLog:

	PR c++/105475
	* coroutines.cc (struct coroutine_info): Add from_address.
	Carries the from_address member we looked up earlier.
	(coro_resume_identifier): Remove.  Unused.
	(coro_init_identifiers): Do not initialize the above.
	(void_coro_handle_address): New variable.  Contains the baselink
	for the std::coroutine_handle<void>::address() instance method.
	(get_handle_type_address): New function.  Looks up and validates
	handle_type::address in a given handle_type.
	(get_handle_type_from_address): New function.  Looks up and
	validates handle_type::from_address in a given handle_type.
	(coro_promise_type_found_p): Remove reliance on
	coroutine_handle<> defaulting the promise type to void.  Store
	get_handle_type_* results where appropriate.
	(get_coroutine_from_address): New helper.  Gets the
	handle_type::from_address BASELINK from a coroutine_info.
	(build_actor_fn): Use the get_coroutine_from_address helper and
	void_coro_handle_address.

gcc/testsuite/ChangeLog:

	PR c++/105475
	* g++.dg/coroutines/pr103868.C: Add std::coroutine_handle
	members we check for now.
	* g++.dg/coroutines/pr105287.C: Ditto.
	* g++.dg/coroutines/pr105301.C: Ditto.
	* g++.dg/coroutines/pr94528.C: Ditto.
	* g++.dg/coroutines/pr94879-folly-1.C: Ditto.
	* g++.dg/coroutines/pr94883-folly-2.C: Ditto.
	* g++.dg/coroutines/pr98118.C: Ditto.
	* g++.dg/coroutines/pr105475.C: New test.
	* g++.dg/coroutines/pr105475-1.C: New test.
	* g++.dg/coroutines/pr105475-2.C: New test.
	* g++.dg/coroutines/pr105475-3.C: New test.
	* g++.dg/coroutines/pr105475-4.C: New test.
	* g++.dg/coroutines/pr105475-5.C: New test.
	* g++.dg/coroutines/pr105475-6.C: New test.
	* g++.dg/coroutines/pr105475-broken-spec.C: New test.
	* g++.dg/coroutines/pr105475-broken-spec-2.C: New test.

0 files changed, 0 insertions, 0 deletions