[clang-tools-extra] [clangd] [C++20] [Modules] Introduce initial support for C++20 Modules (PR #66462)

[kadir çetinkaya via cfe-commits]

================

----------------
kadircet wrote:

again no need for any of these changes, we should just pass `Inputs` as-is to `buildPreamble`.

https://github.com/llvm/llvm-project/pull/66462