c++: robustify testcase [PR109752]

This rewrites the testcase for PR109752 to make it simpler and more
robust (i.e. no longer dependent on r13-4035-gc41bbfcaf9d6ef).

	PR c++/109752

gcc/testsuite/ChangeLog:

	* g++.dg/cpp2a/concepts-pr109752.C: Rename to ...
	* g++.dg/cpp2a/concepts-complete4.C: ... this.  Rewrite.

2 files changed, 13 insertions, 26 deletions

diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-complete4.C b/gcc/testsuite/g++.dg/cpp2a/concepts-complete4.C
new file mode 100644
index 0000000..988b0dd
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/concepts-complete4.C
@@ -0,0 +1,13 @@
+// PR c++/109752
+// { dg-do compile { target c++20 } }
+
+template<class T>
+concept C = requires { sizeof(T); } && T::value; // { dg-error "changed from" }
+
+struct A;
+
+static_assert(!C<A>);
+
+struct A { static constexpr bool value = false; };
+
+static_assert(C<A>); // { dg-error "assert" }
diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-pr109752.C b/gcc/testsuite/g++.dg/cpp2a/concepts-pr109752.C
deleted file mode 100644
index d54ce29..0000000
--- a/gcc/testsuite/g++.dg/cpp2a/concepts-pr109752.C
+++ /dev/null
@@ -1,26 +0,0 @@
-// PR c++/109752
-// { dg-do compile { target c++20 } }
-
-template <typename _Tp, typename... _Args>
-  inline constexpr bool is_constructible_v = __is_constructible(_Tp, _Args...);
-    template<typename _Tp, typename _Up>
-      concept __weakly_eq_cmp_with
- = requires(_Tp __t, _Up __u) {    { __u != __t } ; // { dg-error "changed from" }
- };
-  template<typename _Tp>
-    concept regular =  is_constructible_v<_Tp>  && __weakly_eq_cmp_with<_Tp, _Tp>;
-  template<typename _Iter> concept incrementable = true
-&& regular<_Iter>
-&& requires(_Iter __i) { { __i++ } ;}
-;
-template<typename D>
-struct iterator_interface
-{
-  friend constexpr bool operator>=(D lhs, D rhs) requires __weakly_eq_cmp_with<D, D> { return true; }
-};
-template<typename T>
-struct iterator : iterator_interface<iterator<T>>
-{
-    bool operator==(iterator) const;
-};
-static_assert(incrementable<iterator<int>>); // { dg-error "assert" }