Fixing conflicting macro definitions between curses.h and the standard library.

POSIX allows certain macros to exist with generic names (i.e. refresh(), move(), and erase()) to exist in `curses.h` which conflict with functions found in std::filesystem, among others. This patch undefs the macros in question and adds them to LIBCPP_PUSH_MACROS and LIBCPP_POP_MACROS.

Reviewed By: #libc, philnik, ldionne

Differential Revision: https://reviews.llvm.org/D147356