[OPENMP]Improve use of the global tid parameter.

If we can determined, that the global tid parameter can be used in the
function, better to use it rather than calling __kmpc_global_thread_num
function.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@375134 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed