correct C99 detection for Score-P 8 (credits @rtschueter)

Author: Maximilian

setup.py

@@ -14,6 +14,10 @@
     )
 
 check_compiler = scorep.helper.get_scorep_config("C99 compiler used:")
+if check_compiler is None:
+    check_compiler = scorep.helper.get_scorep_config("C99 compiler:")
+if check_compiler is None:
+    raise RuntimeError("Can not parse the C99 compiler, aborting!")
 if "gcc" in check_compiler:
     gcc_plugin = scorep.helper.get_scorep_config("GCC plug-in support:")
     if not ("yes" in gcc_plugin):