Add tclsh to pid's list of interpreters.


git-svn-id: svn://svn.tartarus.org/sgt@10190 cda61777-01e9-0310-a592-d414129be87e
64-bit cleanness fix in the pidset implementation.

If we write '1 << n' and cast the result to an unsigned long, the 1 is
treated as a signed integer constant, so that shifting it left by 31
is undefined behaviour (and in this case can give 0xffffffff80000000
when the resulting signed thing is cast to unsigned long). Use 1UL
instead to ensure everything is the right type from the word go.


git-svn-id: svn://svn.tartarus.org/sgt@10191 cda61777-01e9-0310-a592-d414129be87e