[committed] c++: Add test for PR c++/93211

[Patrick Palka via Gcc-patches]

The fix for PR c++/90711 also fixed this PR.

gcc/testsuite/ChangeLog:

        PR c++/93211
        PR c++/90711
        * g++.dg/template/koenig11.C: New test.
---
 gcc/testsuite/g++.dg/template/koenig11.C | 11 +++++++++++
 1 file changed, 11 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/template/koenig11.C

diff --git a/gcc/testsuite/g++.dg/template/koenig11.C 
b/gcc/testsuite/g++.dg/template/koenig11.C
new file mode 100644
index 00000000000..d69709bab59
--- /dev/null
+++ b/gcc/testsuite/g++.dg/template/koenig11.C
@@ -0,0 +1,11 @@
+// PR c++/93211
+// { dg-do compile { target c++11 } }
+
+template<typename T>
+void g(T);
+
+template<typename T, decltype(g(T{})) = 0>
+void f() {}
+
+template<typename T, decltype(::g(T{})) = 0>
+void f() {} // { dg-bogus "redefinition" }
-- 
2.26.0.106.g9fadedd637