[clang] [clang-tools-extra] [clangd] Add InsertReplaceEdit for code completion (PR #187623)

[Nathan Ridge via cfe-commits]

HighCommander4 wrote:

@fannheyward thank you for spotting this regression! Would you mind filing a new issue for it so we don't lose track of it?

https://github.com/llvm/llvm-project/pull/187623