In order to check the actual code better, checksrc now ignores
everything that look like preprocessor instructions. It also means
that code in macros are now longer checked.
Note that some rules then still don't need to be followed when code is
exactly below a cpp instruction.
Removes two checksrc exceptions we needed previously because of
preprocessor lines being checked.
Reported-by: Marcel Raad
Fixes#7863Closes#7864
