re PR c++/70634 (ICE on valid code on x86_64-linux-gnu: Segmentation fault (program cc1plus))
PR c++/70634
* pt.c (instantiation_dependent_uneval_expression_p): Split out
from instantiation_dependent_expression_p.
(value_dependent_expression_p): Use it for unevaluated operands.
(instantiation_dependent_r): Don't check value-dependence.
(instantiation_dependent_expression_p): Check
value-dependence of the expression as a whole.
* cp-tree.h: Declare instantiation_dependent_uneval_expression_p.
* semantics.c (finish_decltype_type): Use it.