[libcxx] [test] Call create_directory_symlink when linking directories

This makes the symlinks work properly on windows.

A similar round of cleanup was done in
c41bda7, but these tests were
added after that.

Differential Revision: https://reviews.llvm.org/D97089

Author: mstorsjo

libcxx/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directory/create_directory.pass.cpp

@@ -118,7 +118,7 @@ TEST_CASE(dest_is_symlink_to_dir)
 {
     scoped_test_env env;
     const path dir = env.create_dir("dir");
-    const path sym = env.create_symlink(dir, "sym_name");
+    const path sym = env.create_directory_symlink(dir, "sym_name");
     std::error_code ec = GetTestEC();
     TEST_CHECK(create_directory(sym, ec) == false);
     TEST_CHECK(!ec);

libcxx/test/std/input.output/filesystems/fs.op.funcs/fs.op.create_directory/create_directory_with_attributes.pass.cpp

@@ -147,7 +147,7 @@ TEST_CASE(dest_is_symlink_to_unexisting) {
 TEST_CASE(dest_is_symlink_to_dir) {
   scoped_test_env env;
   const path dir = env.create_dir("dir");
-  const path sym = env.create_symlink(dir, "sym_name");
+  const path sym = env.create_directory_symlink(dir, "sym_name");
   const path attr_dir = env.create_dir("attr_dir");
   {
     std::error_code ec = GetTestEC();