Several source files in our repository have ended up with the executable bit set. This doesn't really affect anything, but it is strange. The biggest problem seems to be in test/suite, where about 1/3 of the Python files there are incorrectly executable. There are other offenders though - you can see a list with find test -executable -type f (or the src directory, depending on where you want to look).
Some method for checking this should also be added - perhaps a s_executable script, or maybe git can do it.