[OMPT] Make sure that OMPT is enabled when accessing internals of the runtime
Redo after revert by hans. The wrong include in one test is fixed.
Make sure that OMPT is enabled in runtime entry points that access internals
of the runtime. Else, return an appropiate value indicating an error or that
the data is not available.
Patch provided by @sconvent
Reviewers: jlpeyton, omalyshe, hbae, Hahnfeld, joachim.protze
Reviewed By: joachim.protze
Tags: #openmp, #ompt
Differential Revision: https://reviews.llvm.org/D47717