2018-07-20  Richard Biener  <rguenther@suse.de>

	PR debug/86585
	* dwarf2out.c (dwarf2out_die_ref_for_decl): Test in_lto_p
	to cover -flto-partition=none.
	
	lto/
	* lto.c (unify_scc): Before we throw away an SCC see if we
	can amend prevailing single-entry SCC with debug refs.

	* g++.dg/lto/pr86585_0.C: New testcase.
	* g++.dg/lto/pr86585_1.C: Likewise.

From-SVN: r262901