Shell files in `/bin` can be made executable

[Japris Pogrammer]

Currently [1] shell scripts in /bin directory seem to be missing x
modifier. I guess that it should be added to them in order to improve their
usage experience a bit.
Is this assumption right?
If yes, then I am ready to propose a simple fix for this [2].

[1]:
https://github.com/openjdk/jdk/blob/f4dc03ea6de327425ff265c3d2ec16ea7b0e1634/bin/
[2]: https://github.com/JarvisCraft/jdk/tree/bin-make-shell-files-executable