Use kernel metadata to differentiate between kernel and device
functions for the NVPTX target.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178418 91177308-0d34-0410-b5e6-96231b3b80d8
Remove old NVPTX cpus and add new NVPTX cpus

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178419 91177308-0d34-0410-b5e6-96231b3b80d8