[Bug c++/125210] [14/15/16/17 Regression] [coroutines] Change in coroutine frame destruction behavior on exception since 14.3

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125210

--- Comment #4 from bootmgr at 163 dot com <bootmgr at 163 dot com> ---
> It's not clear what the correct
> behavior is.

This exact wording question is tracked as CWG2934
(https://cplusplus.github.io/CWG/issues/2934.html).

CWG2934 notes that existing implementations destroy the promise object,
followed by the parameter copies, and then deallocate the coroutine state when 
unhandled_exception()  exits via an exception. This is the expected behavior
based on  [dcl.fct.def.coroutine]/5 .

The GCC 14.2 behavior is the intended behavior. The GCC 14.3 and later
behavior, where the promise destructor is not called and the coroutine state is
leaked, is incorrect.