move findArrayDimensions to ScalarEvolution

we do not use the information from SCEVAddRecExpr to compute the shape of the array,
so a better place for this function is in ScalarEvolution.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208456 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed