[patch, Fortran] LEADZ, POPCNT, POPPAR and TRAILZ for unsigned numbers

[Thomas Koenig]

Hello world,

Playing around with UNSIGNED, I noted that LEADZ and TRAILZ were rejected
for UNSIGNED, which makes no sense.  POPCNT and POPPAR worked, but this
was not documented.  All that was needed for the LEADZ and TRAILZ to work
was to adjust the check routine, so this is a two-character patch
(plus documentation).

Regression-tested. OK for trunk and backport?

Best regards

        Thomas


gcc/fortran/ChangeLog:

        PR fortran/128124
        * gfortran.texi: Note that LEADZ, POPCNT, POPPAR and TRAILZ take
        unsigned arguments.
        * intrinsic.cc (add_functions): LEADZ and TRAILZ also take unsigned
        arguments.
        * intrinsic.texi: Document unsigned arguments for LEADZ, POPCNT, POPPAR
        and TRAILZ.

gcc/testsuite/ChangeLog:

        PR fortran/128124
        * gfortran.dg/unsigned_45.f90: New test.