The roctracer_load, roctracer_unload, and roctrace_flush_buf functions
are not part of the ROCtracer API, and should not be exposed in the API
header file, but keep the functions in the library for backward
compatibility.
Add src/roctracer/backward_compat.cpp to implement retired functions.
Add test/app/backward_compat_test.cpp to test that the retired functions
are still accessible in the latest roctracer library.
Change-Id: I4c94310a7bfccfeae9384dac5db18fc79b4c5b17
Laurent Morichetti