Tag new #else and #endif blocks with comments

include/grpc++/impl/codegen/method_handler_impl.h

@@ -45,9 +45,9 @@ Status CatchingFunctionHandler(Callable&& handler) {
   } catch (...) {
     return Status(StatusCode::UNKNOWN, "Exception in method handler");
   }
-#else
+#else   // GRPC_ALLOW_EXCEPTIONS
   return handler();
-#endif
+#endif  // GRPC_ALLOW_EXCEPTIONS
 }
 
 /// A wrapper class of an application provided rpc method handler.

include/grpc/impl/codegen/port_platform.h

@@ -483,14 +483,14 @@ typedef unsigned __int64 uint64_t;
  * 0 on non-Windows platforms unless the compiler defines __EXCEPTIONS */
 #ifdef GPR_WINDOWS
 #define GRPC_ALLOW_EXCEPTIONS 1
-#else
+#else /* GPR_WINDOWS */
 #ifdef __EXCEPTIONS
 #define GRPC_ALLOW_EXCEPTIONS 1
-#else
+#else /* __EXCEPTIONS */
 #define GRPC_ALLOW_EXCEPTIONS 0
-#endif
-#endif
-#endif
+#endif /* __EXCEPTIONS */
+#endif /* __GPR_WINDOWS */
+#endif /* GRPC_ALLOW_EXCEPTIONS */
 
 #ifndef __STDC_FORMAT_MACROS
 #define __STDC_FORMAT_MACROS