[PATCH] add splay tree for info_ptr -> CU mapping

[Nick Clifton]

Hi Martin,

> bfd/ChangeLog:
> 
> 	* dwarf2.c (struct addr_range): New.
> 	(addr_range_intersects): Likewise.
> 	(splay_tree_compare_addr_range): Likewise.
> 	(splay_tree_free_addr_range): Likewise.
> 	(struct dwarf2_debug_file): Add comp_unit_tree.
> 	(find_abstract_instance): Use the splay tree when searching
> 	for a info_ptr.
> 	(stash_comp_unit): Insert to the splay tree.
> 	(_bfd_dwarf2_cleanup_debug_info): Clean up the splay tree.

Approved - please apply.

Cheers
   Nick