c++: add fixed test [PR118482]

Fixed by r15-9362.

	PR c++/118482

gcc/testsuite/ChangeLog:

	* g++.dg/cpp2a/lambda-uneval31.C: New test.

diff --git a/gcc/testsuite/g++.dg/cpp2a/lambda-uneval31.C b/gcc/testsuite/g++.dg/cpp2a/lambda-uneval31.C
new file mode 100644 (file)
index 0000000..4fedaf8
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/lambda-uneval31.C
@@ -0,0 +1,12 @@
+// PR c++/118482
+// { dg-do compile { target c++20 } }
+
+using what_type = decltype(
+    [](auto&& self,
+        decltype([](decltype(self)&){}) x = {}){ return x; });
+
+what_type x;
+
+int main() {
+    if (x(x)) return 1;
+}