[pushed] c++: Add testcase for already fixed PR [PR103807]

[Patrick Palka via Gcc-patches]

We accept this testcase since r13-806-g221acd67ca50f8.

        PR c++/103807

gcc/testsuite/ChangeLog:

        * g++.dg/cpp2a/lambda-targ1.C: New test.
---
 gcc/testsuite/g++.dg/cpp2a/lambda-targ1.C | 11 +++++++++++
 1 file changed, 11 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/cpp2a/lambda-targ1.C

diff --git a/gcc/testsuite/g++.dg/cpp2a/lambda-targ1.C 
b/gcc/testsuite/g++.dg/cpp2a/lambda-targ1.C
new file mode 100644
index 00000000000..07fa6f9bc19
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp2a/lambda-targ1.C
@@ -0,0 +1,11 @@
+// PR c++/103807
+// { dg-do compile { target c++20 } }
+
+template<auto = +[]{}>
+struct A { };
+
+A x;
+
+int main() {
+  A y;
+}
-- 
2.40.1.552.g91428f078b