Second part of P0482 - char8_t. Reviewed as https://reviews.llvm.org/D55308

llvm-svn: 348828
diff --git a/libcxx/test/std/strings/basic.string.hash/enabled_hashes.pass.cpp b/libcxx/test/std/strings/basic.string.hash/enabled_hashes.pass.cpp
index 01f0121..e6f3d53 100644
--- a/libcxx/test/std/strings/basic.string.hash/enabled_hashes.pass.cpp
+++ b/libcxx/test/std/strings/basic.string.hash/enabled_hashes.pass.cpp
@@ -23,6 +23,9 @@
   {
     test_hash_enabled_for_type<std::string>();
     test_hash_enabled_for_type<std::wstring>();
+#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+    test_hash_enabled_for_type<std::u8string>();
+#endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
     test_hash_enabled_for_type<std::u16string>();
     test_hash_enabled_for_type<std::u32string>();