[Bug libstdc++/57505] [C++11] destructor of std::function should be noexcept

[f.heckenbach@fh-soft.de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57505

--- Comment #1 from Frank Heckenbach <f.heckenbach@fh-soft.de> ---
Created attachment 30244
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30244&action=edit
Test case for enable_shared_from_this

The same applies to std::enable_shared_from_this.