2017-01-09  Richard Biener  <rguenther@suse.de>

	PR debug/79000
	* dwarf2out.c (is_cxx): New overload with context.
	(is_naming_typedef_decl): Use it.

	* g++.dg/lto/pr79000_0.C: New testcase.
	* g++.dg/lto/pr79000_1.c: Likewise.

From-SVN: r244217