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/strings.pass.cpp b/libcxx/test/std/strings/basic.string.hash/strings.pass.cpp
index d74e4857..449ad8f 100644
--- a/libcxx/test/std/strings/basic.string.hash/strings.pass.cpp
+++ b/libcxx/test/std/strings/basic.string.hash/strings.pass.cpp
@@ -44,6 +44,9 @@
 int main()
 {
     test<std::string>();
+#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+    test<std::u8string>();
+#endif
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
     test<std::u16string>();
     test<std::u32string>();