stl / pthreads leak, patch

[Loren James Rittle]

> I realize now that neither test case I have provided demonstrates
> the problem well. I am not sure how to demonstrate the problem with
> a small program. It is possible that it can not be demonstrated with
> a small program.

Then feel free to provide a test case of *any* size (if truly massive
do not put it on the list, rather file a GNATs PR at
http://gcc.gnu.org and upload it as a PR attachment).  I only ask that
it be self-contained within one source file, if at all possible.
Also, we can't agreed to look at any code which may not be made public
so please trim any IPR you wish to retain from the test case.

If you are willing to produce such a case, then I personally commit to
looking at it.

> [How to disable cache]

Recompile and reinstall the entire library after editing
libstdc++-v3/include/bits/c++config to add a macro define for
__USE_MALLOC .  There is no other supported technique to disable this
caching behavior.

Regards,
Loren