[clang] [clang] Fix size and alignment of packed sub-byte integer vectors (PR #161796)

[Steffen Larsen via cfe-commits]

steffenlarsen wrote:

> Do we need similar checks anywhere else we check isPackedVectorBoolType?

Luckily that case was already handled [here](https://github.com/llvm/llvm-project/pull/161796/files#diff-328fcdcf882c121d5c56fdc6cd56c43fdbbb00da171da70f3ba6982c43686a63L2097-L2098) and now [here](https://github.com/llvm/llvm-project/pull/161796/files#diff-328fcdcf882c121d5c56fdc6cd56c43fdbbb00da171da70f3ba6982c43686a63R2098-R2099). 😄 

https://github.com/llvm/llvm-project/pull/161796