PR c++/51213 (again)
* pt.c (deduction_tsubst_fntype): Remove.
(fn_type_unification): Check deduction depth and call
instantiate_template here. Handle default argument access checks.
(determine_specialization): Suppress access control.
(tsubst_decl): Check for excessive deduction depth.
(recheck_decl_substitution): Make sure access control is on.
(type_unification_real): Don't mess with access deferring here.
(get_bindings): Adjust for fn_type_unification return type.
* call.c (enum rejection_reason_code): Drop rr_template_instantiation.
(template_instantiation_rejection): Remove.
(struct rejection_reason): Change targs to num_targs.
(template_unification_rejection, print_z_candidate): Adjust.
(add_template_candidate_real): Adjust for fn_type_unification change.
* class.c (resolve_address_of_overloaded_function): Likewise.
* cp-tree.h: Adjust declaration.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@190664 138bc75d-0d04-0410-961f-82ee72b054a4