[Patch, Fortran] PR37504 Fix special case of PROTECTED pointer assignment

[Tobias Burnus]

* PING *

Tobias Burnus wrote:
> Hi all,
>
> the attached patch fixes
>
>   some_pointer => protected_pointer
>
> which is valid. (Protected pointers' associations may not be changed,
> but their target's value may.) Before gfortran (and sunf95) rejected
> it. See PR and c.l.f for details.
>
> As I saw that the error message looks strange, I debugged it but I have
> not found yet a working patch and thus deferred it to PR37513.
> While debugging I found out that the checks in match.c can never be
> reached as the  match("%v =>") fails earlier. (In match_variable
> is the protected pointer check.) I thus decided to clean up the code
> by removing these checks.
>
> Build and currently regtesting on x86-64-linux.
> OK for the trunk if regtesting suceeds?
> Shall I also apply the expr.c part of the patch to 4.3?
>
> Tobias
>