[clang-tools-extra] [clangd] Allow specifying what headers are always included via "" or <> (PR #67749)

[Andrew Kaster via cfe-commits]

ADKaster wrote:

Yeah seems llvm prefers not to force push PRs, but to keep stacking commits. The squashed commit will have the PR description as the final commit description. The compare button is a bit useless when it has a bunch of changes from main on it (https://github.com/llvm/llvm-project/compare/8a2b22e69f82e3f4caa271b57b998d1c03b21d39..67971ca27ef5e2767aba5cfe2cec1021c4de5ec1)

https://github.com/llvm/llvm-project/pull/67749