[rfa] Make the partial DIE cache more robust

[Joel Brobecker]

> 2005-04-07  Daniel Jacobowitz  <dan@codesourcery.com>
> 
> 	* dwarf2read.c (struct dwarf2_per_cu_data): Reduce length to
> 	30 bits.  Add load_all_dies flag.
> 	(load_partial_dies): Load all DIEs if per_cu->load_all_dies is set.
> 	Load DW_TAG_member by default.  Remove internal_error call.
> 	(find_partial_die): Reload the compilation unit if we can not find
> 	a DIE in the cache.  Call internal_error here if we still can not
> 	find the DIE.

(I know I can't approve patches, but it looks great). If it helps, I can
see if I can merge it into 6.3 and give it a swirl with our Ada compiler
and our Ada examples, where this will likely be useful.

-- 
Joel