pass element size to delinearization

Instead of relying on the delinearization to infer the size of an element,
compute the element size from the base address type. This is a much more precise
way of computing the element size than before, as we would have mixed together
the size of an element with the strides of the innermost dimension.

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@209695 91177308-0d34-0410-b5e6-96231b3b80d8
delinearize does not return a remainder

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@209696 91177308-0d34-0410-b5e6-96231b3b80d8