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

[kadir çetinkaya via cfe-commits]

================
@@ -112,6 +114,9 @@ class ClangdServer {
     /// This throttler controls which preambles may be built at a given time.
     clangd::PreambleThrottler *PreambleThrottler = nullptr;
 
+    /// Enable experimental support for modules.
----------------
kadircet wrote:

this isn't used. can you instead pass the `ModulesManager` directly via opts into `ClangdServer`, instead of adding a new constructor arg?

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