Fix C++ irix6 -g compiler abort.

Fix C++ irix6 -g compiler abort.

	* dwarf2out.c (decl_scope_node): New type.
	(decl_scope_table): Change type to use it.
	(decl_scope_table_allocated, decl_scope_depth): Change type to int.
	(push_decl_scope): Use new type.  New locals containing_scope, i.
	Add code to handle setting previous field.
	(scope_die_for): Change type of local i to int.  Add code to use
	previous field.
	(dwarf2out_init): Use new type.

From-SVN: r17969