Move the tests to libcxx so they no longer need `REQUIRES: libc++`.
Verify tests don't need `REQUIRES: libc++`.
Reviewed By: #libc, ldionne
Differential Revision: https://reviews.llvm.org/D106673
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03
-// REQUIRES: libc++
// These tests require locale for non-char paths
// UNSUPPORTED: libcpp-has-no-localization
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03
-// REQUIRES: libc++
// This test makes sure that the control block implementation used for non-array
// types in std::make_shared and std::allocate_shared is ABI compatbile with the
// UNSUPPORTED: gcc-10
// Test the [[nodiscard]] extension in libc++.
-// REQUIRES: libc++
// template<class I>
// unspecified iter_move;