[libstdc++?] Inappropriate exit cleanup in C++

[dogtopus]

Exiting a C++ applet will cause memory leak. Likely related to cleanup hooks being either not called or not present (like how newlib handles FILE slots).

[dogtopus]

Might be related: the module-wide destructors were previously uncalled during exit. This has been fixed since then.

We need to retest this.

EDIT: Nope, it still leaks.