[GNATS 25913] Spurious diagnostic with no instance of overload function"boost_spawn" matches the argument list

[jhsedg]

Customer bug ID

gnats/25913.C is the full preprocessed test case

Description

​cpfe -DTEST_NUMBER=1 --gnu_version=120100 -w --no_inlining --no_wrap_diagnostics --display_error --error_limit 1 --c
​++20 -tused Test_name.c
​"Test_name.c", line 87004: error #304: no instance of overloaded function "boost::asio::co_spawn" matches the argume
​nt list
​ argument types are: (boost::asio::io_context, boost::asio::awaitable<void, boost::asio::any_io_executor>
​, boost::asio::any_completion_handler<void (std::__exception_ptr::exception_ptr)>)
​ boost::asio::co_spawn(ctx, void_returning_coroutine(),
​ ^
​
​Error limit reached.
​1 error detected in the compilation of "Test_name.c".