Patch to use concat instead of xmalloc/sprintf for JAVA dir

[Kaveh R. Ghazi]

 > From: Mark Mitchell <mark@codesourcery.com>
 > 
 > NULL_RTX and NULL_TREE provide an additional level of protection, even
 > with prototypes: many compilers will at least warn if `(tree) 0' is
 > passed to a function that expects an `rtx'.

Good point.  I withdraw my comments about NULL_RTX/NULL_TREE and only
advocate removing NULL_PTR now.
--
Kaveh R. Ghazi			Engagement Manager / Project Services
ghazi@caip.rutgers.edu		Qwest Internet Solutions