Handle mpi+omp case in macro generation (#33)

Added a special case for the 'mpi+omp' parallelism model to generate
the macro '-DUSE_MPI_OMP' instead of the default uppercase substitution.

Author: harshithamenon

drivers/cpp/cpp_driver_wrapper.py

@@ -90,7 +90,10 @@ def compile(
             compile_process = build_kokkos(driver_src, os.path.dirname(output_path), problem_size=problem_size)
         else:
             binaries_str = ' '.join(binaries)
-            macro = f"-DUSE_{self.parallelism_model.upper()}"
+            if self.parallelism_model == "mpi+omp":
+                macro = "-DUSE_MPI_OMP"
+            else:
+                macro = f"-DUSE_{self.parallelism_model.upper()}"
             cmd = f"{CXX} {CXXFLAGS} -Icpp -Icpp/models {macro} {binaries_str} -o {output_path}"
             try:
                 compile_process = run_command(cmd, timeout=self.build_timeout, dry=self.dry)