dwarf2out patch for incomplete types

[Jeffrey A Law]

  In message < 199906030931.CAA18793@yorick.cygnus.com >you write:
  > If we never deal with a type directly, only through pointers, we will never
  > get another chance to write out the debugging info for the class, because
  > we have marked the pointer type TREE_ASM_WRITTEN.  So remember what classes
  > we hope to see more from.
  > 
  > Checked in on the mainline and on the branch.
  > 
  > Thu Jun  3 02:15:07 1999  Jason Merrill  <jason@yorick.cygnus.com>
  > 
  > 	* dwarf2out.c (add_incomplete_type): New fn.
  > 	(gen_struct_or_union_type_die): Call it.
  > 	(retry_incomplete_types): New fn.
  > 	(dwarf2out_finish): Call it.
Thanks.  Any chance the dwarf1 code has the same bug?  Robert Lipe's tests
are showing a lot of dwarf1 related problems with references to undefined 
labels and such.  I haven't had a chance to look at them yet though.

jeff