[Fortran-Experiments]: patch for error checking on binding labels and derived types, etc.

[Christopher D. Rickett]

>
> I didn't add a test case yet, because there is one missing warning and
> one wrong warning:
> -----------------------------------
> ! { dg-do "compile" }
> ! Dummy arguments which are functions are allowed to have
> ! the Bind(c) flag set.
>
> MODULE OpenGL_glut
> IMPLICIT NONE
>
> ! Notes:
> ! (1) gives the wrong warning: "Variable 'func' is a parameter to the
> !     BIND(C) procedure 'glutcreatemenu' but may not be C interoperable"
> ! (2) gives no warning although integer has no C interop. kind.
>
> INTERFACE
>  FUNCTION glutCreateMenu(func) BIND(C,NAME="glutCreateMenu")
>    use iso_c_binding   ! ^^^^<<<<< (1)
>    INTEGER :: glutCreateMenu   ! <<<<<<<< (2)
>    INTERFACE                   ! The dummy argument 'func'
>      SUBROUTINE func() BIND(C) ! is allowed to have the bind(c) flag set
>      END SUBROUTINE func
>    END INTERFACE
>  END FUNCTION glutCreateMenu
> END INTERFACE
> END MODULE OpenGL_glut
>
> ! { dg-final { cleanup-modules "OpenGL_glut" } }
> -----------------------------------
>

i moved the verification of bind(c) procedures to resolve_fl_procedure, and
i put the verification of the parameters there also.  now, the above code 
reports:

tobias9.f03:10.25:

   FUNCTION glutCreateMenu(func) BIND(C,NAME="glutCreateMenu")
                         1
Warning: Variable 'glutcreatemenu' at (1) may not be a C interoperable 
kind but it is bind(c)


i've also created a new test case that tests interfaces and contained 
procedures to make sure they're caught with the testing in the new place. 
i'll include it in my next patch soon.

Chris