[clang] Reland "[clang][modules-driver] Add support for C++ named modules and import std" (2nd attempt) (PR #194475)

[antoine moynault via cfe-commits]

antmox wrote:

Hi, this also breaks bot clang-armv8-quick : https://lab.llvm.org/buildbot/#/builders/154


https://github.com/llvm/llvm-project/pull/194475