C++ PATCH for c++/79500, ICE with non-template deduction guide

[Jason Merrill]

DECL_TEMPLATE_RESULT doesn't work on a non-template, so let's use
STRIP_TEMPLATE instead.

Tested x86_64-pc-linux-gnu, applying to trunk.

commit 9f99104a12b72006253c0ce5f0b046ada82eb354
Author: Jason Merrill <ja...@redhat.com>
Date:   Sun Feb 19 14:01:51 2017 -0800

            PR c++/79500 - ICE with non-template deduction guide
    
            * pt.c (do_class_deduction): Use STRIP_TEMPLATE rather than
            DECL_TEMPLATE_RESULT.

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 9e6ce8d..46e6498 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -25118,7 +25118,7 @@ do_class_deduction (tree ptype, tree tmpl, tree init, 
int flags,
     {
       tree t = cands;
       for (; t; t = OVL_NEXT (t))
-       if (DECL_NONCONVERTING_P (DECL_TEMPLATE_RESULT (OVL_CURRENT (t))))
+       if (DECL_NONCONVERTING_P (STRIP_TEMPLATE (OVL_CURRENT (t))))
          break;
       if (t)
        {
@@ -25126,7 +25126,7 @@ do_class_deduction (tree ptype, tree tmpl, tree init, 
int flags,
          for (t = cands; t; t = OVL_NEXT (t))
            {
              tree f = OVL_CURRENT (t);
-             if (!DECL_NONCONVERTING_P (DECL_TEMPLATE_RESULT (f)))
+             if (!DECL_NONCONVERTING_P (STRIP_TEMPLATE (f)))
                pruned = build_overload (f, pruned);
            }
          cands = pruned;
diff --git a/gcc/testsuite/g++.dg/cpp1z/class-deduction29.C 
b/gcc/testsuite/g++.dg/cpp1z/class-deduction29.C
new file mode 100644
index 0000000..efffe3d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/class-deduction29.C
@@ -0,0 +1,6 @@
+// PR c++/79500
+// { dg-options -std=c++1z }
+
+template<typename T> struct A {};
+A(...) -> A<int>;
+A a = {};