[JAVA] Fix bootstrap failure on Tru64

[Andrew Haley]

Roger Sayle writes:
 > 
 > Ok for mainline?
 > 
 > 
 > 2004-04-12  Roger Sayle  <roger@eyesopen.com>
 > 
 > 	* resource.c (write_resource_constructor): Guard call to possibly
 > 	NULL targetm.asm_out.constructor with targetm.have_ctors_dtors.

I'd still like a warning, please.

Andrew.