on MSYS thinks csh is tcsh

[plicease]

$ tcsh
> perl -MShell::Guess -MYAML= -E 'say Dump(Shell::Guess->running_shell)'
--- !!perl/hash:Shell::Guess
c: 1
default_location: /bin/csh
name: c
unix: 1

[plicease]

even worse:

For $^O eq 'MSWin32':

$ tcsh
> perl -MShell::Guess -MYAML= -E 'say Dump(Shell::Guess->running_shell)'
--- !!perl/hash:Shell::Guess
cmd: 1
default_location: C:\Windows\system32\cmd.exe
name: cmd
win32: 1

[simbabque]

I think I've got a fix for Linux. Creating a PR in a moment.

I can confirm the Windows problem with the tcsh.exe from ftp://ftp.astron.com/pub/tcsh/beta/. Not sure how to fix that though. There's nothing in %ENV.