[clang] fix regression deducing pack expansion arguments introduced by D110216

This test case had been missing when the original code
was introduced by 2fcb863b2b278.

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Differential Revision: https://reviews.llvm.org/D114207

GitOrigin-RevId: 85914b757015dfbc780dc254696acb95b8dc7679
2 files changed