[GPGPU] Do not create copy statements when targetting managed memory
Summary:
They are not used and consequently do not even need to be computed. This reduces
the overall compile time for our kernel from 1m33s to 17s.
Reviewers: Meinersbur, bollu, singam-sanjay
Reviewed By: bollu
Subscribers: nemanjai, pollydev, llvm-commits, kbarton
Tags: #polly
Differential Revision: https://reviews.llvm.org/D36868
git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@311157 91177308-0d34-0410-b5e6-96231b3b80d8