File permissions, shebangs in repos/distfiles

Tcl.pm and Tcl::Tk have various files with =E2=80=9Cincorrect=E2=80=9D =
permissions, specifically files that should or should not be marked as =
executable. Files like .pl or .t I would think should be executable, =
while .pm, .xs, or image formats should not.

There=E2=80=99s also files with shebangs like =E2=80=9C#!perl -w=E2=80=9D,=
 which at a minimum should have the -w flag replaced by `use warnings;`. =
At least one file (perl-tcl-tk/test-for-tk.tcl) is executable but is =
missing a shebang. However, I=E2=80=99m not familiar with what an =
appropriate shebang for CPAN dist scripts should be; supposedly =
there=E2=80=99s problems with (or enough people dislike) putting e.g. =
`#!/usr/bin/env perl`.

I can send a PR with =E2=80=9Cfixed=E2=80=9D permissions, but I=E2=80=99m =
not aware of a way to enforce that they don=E2=80=99t change. The =
shebangs I would need more advice on.=