C++ PATCH to decl_namespace_list

[Jason Merrill]

We weren't clearing decl_namespace_list properly across template
instantiations, which caused confusion.

Applied to trunk only.

2001-04-12  Jason Merrill  <jason_merrill@redhat.com>

	* cp-tree.h (decl_namespace_list): New macro.
	(struct saved_scope): Add decl_ns_list.
	* decl.c (mark_saved_scope): Mark it.
	* decl2.c: Lose static decl_namespace_list.
	(init_decl2): Don't save it.