Struct type arguments for generic quicksort

[ansharlubis]

Building on #2956 and referring back to #2266, I added another template instantiation where the argument is a struct type:

    subroutine test_template()
        ...
        instantiate qsort_t(my_type, lt_my_type), only: qsort_my_type => qs
        call quicksort{my_type, lt_my_type}(xm, 1, 10)
        ...
    end subroutine

Where my_type is

module template_sort_02_type
    implicit none
    public :: my_type, my_type_lt

    type my_type
        real :: d
    end type

contains

    pure elemental function lt_my_type(lhs, rhs) result(res)
        type(my_type), intent(in) :: lhs, rhs
        logical :: res
        res = lhs%d <= rhs%d
    end function

end module

[certik]

Beautiful, good stuff!