llvm-project

2f3fa32e - [clang][www] Replace mailing list reference with Discourse forum link (#228676)

[clang][www] Replace mailing list reference with Discourse forum link (#228676) LLVM is now migrating from the mailing lists to Discourse (https://llvm.org/docs/DiscourseMigrationGuide.html), but https://clang.llvm.org still suggests signing up for a mailing list. This PR replaces that recommendation with the Clang Frontend Discourse forum.