swift

9dd87e9c - [CodeCompletion] Fix ASAN failure when completing in parameter packs

[CodeCompletion] Fix ASAN failure when completing in parameter packs Whe completing in parameter packs, we were calling `getParameterAt` with `Res.FuncDeclRef`. But the substitution map in `Res.FuncDeclRef` contained type variables that were allocated in the constraint system’s arena. And that arena had been freed when we call this from `deliverResults`. The fix is to compute the optional parameters in advance in `sawSolutionImpl` rdar://109093909