[clang] [Clang][P1061] Consolidate ResolvedUnpexandedPackExpr into FunctionParmPackExpr (PR #125394)

[Jason Rice via cfe-commits]

ricejasonf wrote:

@Sirraide I did try it and the bug persists. The `LHS` is a RecoveryExpr, so I am not sure how to approach that.

https://github.com/llvm/llvm-project/pull/125394