[clang-tools-extra] [clangd] Check for valid location in ExtractionContext::exprIsValidOutside (PR #71162)

[Björn Pettersson via cfe-commits]

bjope wrote:

Hi reviewers. I don't know much about clangd so looking for feedback on this patch to know if it is the correct thing to do.
Not sure exactly who knows this part of the code, so please let me know if someone else should review this!

https://github.com/llvm/llvm-project/pull/71162