what is src/missing-string.c:vasprintf used for

[Simon Josefsson]

There is am implementation of vasprintf for MinGW in
src/missing-string.c in libgcrypt.  However, I cannot find any calls to
vasprintf in libgcrypt itself.  What is this code used for?

If the code doesn't serve any purpose, it would be nice to remove it to
avoid static library name space pollution.

Thanks,
/Simon