PR c++/78948 - instantiation from discarded statement
	* parser.h (struct cp_parser): Remove in_discarded_stmt field.
	* cp-tree.h (in_discarded_stmt): Declare it.
	(struct saved_scope): Add discarded_stmt bitfield.
	(in_discarded_stmt): New macro.
	* decl2.c (mark_used): Check it.
	* parser.c (cp_parser_selection_statement): Adjust.
	(cp_parser_jump_statement): Adjust.

From-SVN: r244206