Upstreaming OMPD

[jprotze]

• integrate the LLVM-openmp branch into an llvm-project branch: https://github.com/OpenMPToolsInterface/llvm-project/tree/ompd-tests

• merge with master and keep up to date: https://github.com/OpenMPToolsInterface/llvm-project/tree/ompd-tests-merge-master

• Split the diff into junks and upload to https://reviews.llvm.org/differential/:

  • changes in openmp/runtime
  • changes in libomptarget
  • libompd/src (host specific)
    • TargetValue
    • callbacks
    • handle api calls
    • other query api calls
    • ICV queries
  • libompd/src (device specific)
  • libompd/tests
  • libompd/gdb-plugin

drop gdb-wrapper
drop cuda_examples (or move to libompd/tests)