PR other/90695 reduce testcase to remove library dependency

This reproduces the original ICE fixed by r178857 (tested at r178852 and
r178860), without depending on a libstdc++ header that keeps changing.

The number of errors differs between C++14 and C++17 modes, so the fixed
test uses dg-excess-errors to match any number of them. The precise
errors aren't what's being tested for here anyway, the point of the test
is to verify the ICE in PR 50391 is fixed.

	PR other/90695
	* g++.dg/cpp0x/noexcept15.C: Remove dependency on library header.

From-SVN: r272121

gcc/testsuite/ChangeLog

+2019-06-10  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR other/90695
+	* g++.dg/cpp0x/noexcept15.C: Remove dependency on library header.
+
 2019-06-10  Jakub Jelinek  <jakub@redhat.com>
 
 	* c-c++-common/gomp/scan-1.c: New test.

gcc/testsuite/g++.dg/cpp0x/noexcept15.C

 // PR c++/50391
 // { dg-do compile { target c++11 } }
 
-#include <type_traits>
+namespace std
+{
+  template<typename T, T Val>
+    struct integral_constant
+    { static constexpr T value = Val; };
+
+  template<typename T>
+    struct is_abstract
+    : integral_constant<bool, __is_abstract(T)>
+    { };
+
+  template<typename T, bool = is_abstract<T>::value>
+    struct is_destructible
+    : integral_constant<bool, true>
+    { };
+
+  template<typename T>
+    struct is_destructible<T, true>
+    : integral_constant<bool, false>
+    { };
+
+  template<typename T>
+    struct is_nothrow_move_constructible
+    : is_destructible<T>
+    { };
+
+  template<typename T>
+    struct decay
+    { typedef T type; };
+
+  template<typename T>
+    struct decay<T&>
+    { typedef T type; };
+
+} // std
 
 template<class Tp>
   struct single
   {
-    Tp elem;  // { dg-error "incomplete type" }
+    Tp elem;
 
     constexpr single(const Tp& e)
     : elem(e) { }
@@ -30,3 +64,5 @@ foo(Blob *b)
 {
   make_single(*b);
 }
+
+// { dg-excess-errors "incomplete type|not a member" }