backport: re PR c++/89767 (ICE with tuple and optimization)

backport: re PR c++/89767 (ICE with tuple and optimization)

	Backported from mainline
	2019-03-21  Jakub Jelinek  <jakub@redhat.com>

	PR c++/89767
	* parser.c (cp_parser_lambda_introducer): Add ids and first_capture_id
	variables, check for duplicates in this function.
	* lambda.c (add_capture): Don't check for duplicates nor use
	IDENTIFIER_MARKED.
	(register_capture_members): Don't clear IDENTIFIER_MARKED here.

	* g++.dg/cpp1y/lambda-init18.C: New test.
	* g++.dg/cpp1y/lambda-init19.C: New test.
	* g++.dg/cpp1y/pr89767.C: New test.

From-SVN: r275139