* cp-tree.def (TINST_LEVEL): Document TINST_IN_SYSTEM_HEADER_P.
* cp-tree.h (struct tinst_level): Add in_system_header_p.
(TINST_IN_SYSTEM_HEADER_P): New macro.
(make_tinst_level): Remove.
* pt.c (lookup_template_class): Preserve DECL_IN_SYSTEM_HEADER on
the instantiated class.
(push_tinst_level): Do not use make_tinst_level. Set
TINST_IN_SYSTEM_HEADER_P.
(pop_tinst_level): Likewise.
(instantiate_class_template): Set in_system_header.
(instantiate_pending_templates): Likewise.
* tree.c (make_tinst_level): Remove.
PR c++/20145
* g++.dg/warn/Wdtor1.C: New test.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@97854
138bc75d-0d04-0410-961f-
82ee72b054a4