[clang-tools-extra] [clang] [Sema][clangd] add noexcept to override functions during code completion (PR #75937)

[Younan Zhang via cfe-commits]

zyn0217 wrote:

In addition to Nathan’s advice, I have a question about the commit message
> if the functions override a noexcept virtual function.
I didn't see anything reflecting this condition; are you still working on this patch? Would you mind adding a WIP prefix to the title before everything is ready? Thank you!

https://github.com/llvm/llvm-project/pull/75937