where to write small reusable functions ?

Hi,

I'm working to implement a new feature to pg_dump: the ability to dump
objects like function, indexes... And I notice that there some usefull
functions like pg_malloc, pg_calloc... So I've added pg_free to avoid the
sequence if-not-null-free-point-to-NULL, now I'd like to add a function
pg_strcat like this
char *
pg_strcat (char *dest,char *src)
{
/* pg_realloc is a safer function than realloc */
dest=pg_realloc(dest,strlen(dest)+strlen(src)+1);

strcat(dest,src);
return dest;
}

But, in that case, those functions are only usable for pg_dump, what about
the rest of code ? We don't have a central location for those small reusable
snippets of code ?

Regards,

.D.