[clang-tools-extra] [clangd] Extract to Function: mark unmodified captured parameters const (PR #225666)

[Christian Kandeler via cfe-commits]

ckandeler wrote:

> I am just trying to say that maybe using `ExprMutationAnalyzer` is not a correct way here and we need a deeper investigation here instead.

Turns out you were right; it introduces quadratic behavior (due to aliasing checks).

> We already have ExtractionZoneVisitor which traverses all DeclRefExpr.

Using that one instead now.

https://github.com/llvm/llvm-project/pull/225666