[OPENMP50]Treat range-based for as canonical loop.

According to OpenMP 5.0, range-based for is also considered as a
canonical form of loops.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@373939 91177308-0d34-0410-b5e6-96231b3b80d8
27 files changed