Mark destroying delete test as UNSUPPORTED with clang 7

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@365856 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/std/language.support/support.dynamic/destroying_delete_t.pass.cpp b/test/std/language.support/support.dynamic/destroying_delete_t.pass.cpp
index 2ca6d19..834222c 100644
--- a/test/std/language.support/support.dynamic/destroying_delete_t.pass.cpp
+++ b/test/std/language.support/support.dynamic/destroying_delete_t.pass.cpp
@@ -15,7 +15,7 @@
 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
 
 // UNSUPPORTED: apple-clang-9, apple-clang-10
-// UNSUPPORTED: clang-6
+// UNSUPPORTED: clang-6, clang-7
 
 #include <new>