calculateByteProvider only cares about scalars or a single element
within a vector. For the later there is the VectorIndex parameter to
identify the element. All other properties, and specificially Index, are
related to the underyling scalar type and thus when taking the size of a
type it's the scalar size that matters.
Fixes https://github.com/llvm/llvm-project/issues/148387
bd4e7f5f5d