re PR c++/83644 (ICE using type alias from recursive decltype in noexcept or return type)

	PR c++/83644
	* g++.dg/cpp1z/pr83644.C: New test.

From-SVN: r256082

gcc/testsuite/ChangeLog

@@ -3,6 +3,9 @@
 	PR c++/81860
 	* g++.dg/cpp0x/inh-ctor30.C: New test.
 
+	PR c++/83644
+	* g++.dg/cpp1z/pr83644.C: New test.
+
 2018-01-01  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/83076

gcc/testsuite/g++.dg/cpp1z/pr83644.C

+// PR c++/83644
+// { dg-do compile }
+// { dg-options -std=c++17 }
+
+namespace std {
+template <typename> bool is_invocable_v;
+}
+template <typename F> auto compose(F) {
+  [](auto... objs) noexcept(std::is_invocable_v<decltype(objs)...>){};
+}
+
+auto f() { compose(3); }