[clang-tools-extra] [clangd] Enable parsing of forwarding functions in the preamble by default (PR #127359)

[kadir çetinkaya via cfe-commits]

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

thanks, as long as we're keeping the underlying option I think this makes sense! we can flip it in production if we see big regressions

https://github.com/llvm/llvm-project/pull/127359