can't intentionally throw in constexpr

Author: vinay-deshmukh

libcxx/test/std/containers/associative/map/map.access/at.pass.cpp

@@ -42,11 +42,16 @@ TEST_CONSTEXPR_CXX26 bool test() {
     assert(m.at(4) == 4.5);
     assert(m.at(5) == 5.5);
 #ifndef TEST_HAS_NO_EXCEPTIONS
+
+// throwing is not allowed in constexpr
+#if TEST_STD_VER < 26
     try {
       TEST_IGNORE_NODISCARD m.at(6);
       assert(false);
     } catch (std::out_of_range&) {
     }
+#endif
+
 #endif
     assert(m.at(7) == 7.5);
     assert(m.at(8) == 8.5);