[libc++] Add a script to automatize updating test for a new header.

Idea from D92525.
This script globs include/ directory and updates the tests in test/libcxx.
This patch does not generate module.modulemap nor CMakeLists.txt.

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D92656

GitOrigin-RevId: 6fd5a94eeb9acca783549df26b2e6319df8ab0a8
5 files changed