[flang] Missing diagnostic for duplicate type parameter identifiers

Consider the following code

```fortran
module m
type base (k)
integer, kind :: k = 4
end type

type, extends(base) :: child (k) !<-- illegal
integer, len :: k = 10
end type
end module
```

It is illegal to declare a type parameter with the same name as the other type parameter in its parent type.

Flang compiles the code successfully.
All ifx, gfortran and XLF issue an error message.

Start by running Flang on the Fortran reproducer in this issue and trace the semantic handling of derived-type parameters and inheritance. Done means Flang rejects the duplicate `k` parameter in `child` with a diagnostic, consistent with the other compilers mentioned.

Written by the indexing model from the issue text.