[Flang] Support passing a function that returns procedure pointer as actual...

[Flang] Support passing a function that returns procedure pointer as actual corresponding to a procedure dummy. (#80891)

Flang crashes with the following case. The problem is we missed the case
when passing a reference to a function that returns a procedure pointer
as actual that corresponds to a procedure dummy. This PR is to fix that.

```
  PROGRAM main
  IMPLICIT NONE
  INTERFACE
    FUNCTION IntF(Arg)
      integer :: Arg, IntF
    END FUNCTION
  END INTERFACE

  INTERFACE
    FUNCTION RetPtr(Arg)
      IMPORT
      PROCEDURE(IntF) :: Arg
      PROCEDURE(IntF), POINTER :: RetPtr
    END FUNCTION
  END INTERFACE

  CALL ModSub(RetPtr(IntF))
  contains
    SUBROUTINE ModSub(Fun1)
    PROCEDURE(IntF) :: Fun1
    END SUBROUTINE
  END
  ```