[clang] [clang][AST] fix ast-print of `extern <lang>` with >=2 declarators (PR #93131)

[via cfe-commits]

gulfemsavrun wrote:

> Unfortunately, I don't have the right to revert.

No worries, and I reverted for you. When you have the fix ready, I'm happy to verify it on our builders before you reland.


https://github.com/llvm/llvm-project/pull/93131