[OPENMP] Limit the loop counters to 64 bits for the worksharing loops

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@219113 91177308-0d34-0410-b5e6-96231b3b80d8
[OPENMP] Fix target triple of a test, which uses __int128 type

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@219114 91177308-0d34-0410-b5e6-96231b3b80d8