[Polly][PPCGCodeGen] OpenCL now gets kernel argument size from PPCG CodeGen

Summary: PPCGCodeGeneration now attaches the size of the kernel launch parameters at the end of the parameter list. For the existing CUDA Runtime, this gets ignored, but the OpenCL Runtime knows to check for kernel-argument size at the end of the parameter list. (The resulting parameters list is twice as long. This has been accounted for in the corresponding test cases).

Reviewers: grosser, Meinersbur, bollu

Reviewed By: bollu

Subscribers: nemanjai, yaxunl, Anastasia, pollydev, llvm-commits

Tags: #polly

Differential Revision: https://reviews.llvm.org/D32961

llvm-svn: 302515