C++: Allow .inc files to be included

Author: rajivshah3

cpp/ql/src/jsf/4.06 Pre-Processing Directives/AV Rule 32.ql

@@ -18,6 +18,7 @@ from Include i, File f, string extension
 where
   f = i.getIncludedFile() and
   extension = f.getExtension().toLowerCase() and
+  extension != "inc" and
   extension != "inl" and
   extension != "tcc" and
   extension != "tpp" and