[clang-tools-extra] [clangd] Store full decl/def range with symbol locations (PR #118102)

[Christian Kandeler via cfe-commits]

ckandeler wrote:

*sigh*
I want to use clangd for this purpose because it produces correct results particularly with non-trivial constructs, so I'm afraid 
that using such textual heuristics would kill that advantage.

I'll give it a try, though.

https://github.com/llvm/llvm-project/pull/118102