[clang-tools-extra] [clang-doc] emit IsBuiltIn and IsTemplate for types (PR #146149)

[Paul Kirth via cfe-commits]

https://github.com/ilovepi approved this pull request.

LGTM. Maybe use `[clang-doc] Serialize IsBuiltIn and IsTemplate for types` as the title?

https://github.com/llvm/llvm-project/pull/146149