how to find out if stringobject is built with CACHE_HASH

[ramb at synopsys.com]

I am working on a module where I need a string table. From
looking at the source in stringobject.h I see that by default
for 1.5.2 python strings are already stored in a string table.
But the user is free to build a version of python without this
feature.

Is there a way I can detect this at run time? It would be nice if
my module could detect that some essential Python feature was missing
and issue an appropriate error message. I just dont know how to get
the info I need...

Thanks for any info.
-Ram