[clang-tools-extra] [clangd] [Modules] Support Reusable Modules Builder (PR #106683)

[kadir çetinkaya via cfe-commits]

================
@@ -85,19 +85,20 @@ class PrerequisiteModules {
 /// different versions and different source files.
 class ModulesBuilder {
----------------
kadircet wrote:

> I was told we don't like forward declaration in clangd

Yes in theory this is also a forward declaration, but it's not in the same bucket as others. It's here to hide an implementation detail. Since the class is declared in a private section and implemented in the CC file, no user can actually see a definition.

> And if we can do that, I like the style too.

glad to hear that. i think this should simplify the changes a lot!

https://github.com/llvm/llvm-project/pull/106683