Overloading binary and unary operators

[certik]

The bug, reported at https://fortran-lang.discourse.group/t/intel-fortran-compiler-bug-overloading-binary-and-unary-operator-and-use-with-extended-types/5836/10:

module mo_vec
  type :: typ1
    real :: x
  contains
    procedure :: diff, neg
    generic :: operator(-) => diff, neg
  end type typ1
  ! extended type
  type, extends(typ1) :: typ2
  end type typ2
contains
  pure type(typ1) function diff(this, that)
    class(typ1), intent(in) :: this, that
    diff = typ1(this%x-that%x)
  end function diff
  pure type(typ1) function neg(this)
    class(typ1), intent(in) :: this
    neg = typ1(-this%x)
  end function neg
end module mo_vec

program vec_test
  use mo_vec, only: typ2
  type(typ2) :: var1 = typ2(1.), var2 = typ2(2.)
  print *, -var2     ! error #5633: **Internal compiler error
  print *, var1-var2 ! error #6355: This binary operation is invalid for this data type.
end program vec_test

Both the print statements fail for LFortran also.

[czgdp1807]

I am working on it.