[clang] [clang] Fix crash in VisitVarTemplatePartialSpecializationDecl on failed instantiation (PR #200161)

[Aayush Shrivastava via cfe-commits]

iamaayushrivastava wrote:

> Almost all of the clang maintainers are currently out for a conference. Please ping again in 7 days.

Thank you for the update. I appreciate your time and will follow up again in about a week.

https://github.com/llvm/llvm-project/pull/200161