Fix PR c++/70822 (bogus error with parenthesized SCOPE_REF)

gcc/cp/ChangeLog:

	PR c++/70822
	PR c++/70106
	* cp-tree.h (REF_PARENTHESIZED_P): Make this flag apply to
	SCOPE_REFs too.
	* pt.c (tsubst_qualified_id): If REF_PARENTHESIZED_P is set
	on the qualified_id then propagate it to the resulting
	expression.
	(do_auto_deduction): Check REF_PARENTHESIZED_P on SCOPE_REFs
	too.
	* semantics.c (force_paren_expr): If given a SCOPE_REF, just set
	its REF_PARENTHESIZED_P flag.

gcc/testsuite/ChangeLog:

	PR c++/70822
	PR c++/70106
	* g++.dg/cpp1y/auto-fn32.C: New test.
	* g++.dg/cpp1y/paren4.C: New test.

From-SVN: r236792