[clang] Make variables of undeduced types to have dependent alignment

Without this patch `VarDecl::hasDependent()` checks only undeduced auto types, so can give false negatives result for other undeduced types.
This lead to crashes in sequence `!VarDecl::hasDepentent()` => `getDeclAlign()`.

It seems this problem appeared since D105380

Reviewed By: mizvekov

Differential Revision: https://reviews.llvm.org/D135362