[libc++] Add missing test for std::hash<std::filesystem::path>

[ldionne]

Poke CI

[ldionne]

Fix some CI issues

libcxx/test/std/input.output/filesystems/class.path/path.member/path.hash_enabled.pass.cpp

+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03
+
+// <filesystem>
+
+// Test that <filesystem> provides all of the arithmetic, enum, and pointer
+// hash specializations.
+
+#include <filesystem>
+
+#include "poisoned_hash_helper.h"
+
+int main(int, char**) {
+  test_library_hash_specializations_available();
+  test_hash_enabled_for_type<std::filesystem::path>();
+
+  return 0;
+}

libcxx/test/std/input.output/filesystems/class.path/path.member/path.compare.pass.cpp

 // bool operator!=(path const&, path const&) noexcept;
 // bool operator< (path const&, path const&) noexcept;
 // bool operator<=(path const&, path const&) noexcept;
 // bool operator> (path const&, path const&) noexcept;
 // bool operator>=(path const&, path const&) noexcept;
 // strong_ordering operator<=>(path const&, path const&) noexcept;
 //
 // size_t hash_value(path const&) noexcept;
+// template<> struct hash<filesystem::path>;
 
 #include "filesystem_include.h"
 #include <type_traits>
 #include <vector>
 #include <cassert>
 
 #include "test_macros.h"
 #include "test_comparisons.h"