C++ PATCH for c++/65195 (variable template of reference type)

[Jason Merrill]

We were missing a convert_from_reference.

Tested x86_64-pc-linux-gnu, applying to trunk and 5.

commit f1f2cd02b7e4549657cf6eeab1d7eae0466ac7a8
Author: Jason Merrill <ja...@redhat.com>
Date:   Wed Aug 5 11:46:48 2015 -0400

    	PR c++/65195
    	PR c++/66619
    	* semantics.c (finish_id_expression): Call convert_from_reference
    	for variable template.

diff --git a/gcc/cp/semantics.c b/gcc/cp/semantics.c
index 44f9f7a..d42838e 100644
--- a/gcc/cp/semantics.c
+++ b/gcc/cp/semantics.c
@@ -3564,6 +3564,7 @@ finish_id_expression (tree id_expression,
 	{
 	  decl = finish_template_variable (decl);
 	  mark_used (decl);
+	  decl = convert_from_reference (decl);
 	}
       else if (scope)
 	{
diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ37.C b/gcc/testsuite/g++.dg/cpp1y/var-templ37.C
new file mode 100644
index 0000000..11021a3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/var-templ37.C
@@ -0,0 +1,23 @@
+// PR c++/65195
+// { dg-do compile { target c++14 } }
+
+template<typename T>
+T constant {};
+
+template<typename T>
+struct foo {
+    int operator()() const
+    { return 3; }
+};
+
+template<typename T>
+auto& f = constant<foo<T>>;
+
+int main()
+{
+    // fine
+    auto& ref = f<int>; ref();
+
+    // error: f<int> cannot be used as a function
+    f<int>();
+}
diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ40.C b/gcc/testsuite/g++.dg/cpp1y/var-templ40.C
new file mode 100644
index 0000000..0a952c4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/var-templ40.C
@@ -0,0 +1,9 @@
+// PR c++/66619
+// { dg-do compile { target c++14 } }
+
+int y;
+template<class T> T val1 = y;
+auto&& x1 = val1<int&>;
+
+template<class T> T val2 = 0;
+auto&& x2 = val2<int&&>;