[PATCH] Fix Fortran ICE due to realloc_string_callback bug (PR fortran/71204)

[Thomas Koenig]

Hi Jakub,

>
> We ICE at -O0 while compiling the testcase below, because we don't reset
> two vars that are reset in all other places in frontend-passes.c when
> starting to process an unrelated statement.  Without this,
> we can emit some statement into a preexisting block that can be elsewhere
> in the current procedure or as in the testcase in completely different
> procedure.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk/6/5?

OK for all affected branches.

Thanks for the patch!

	Thomas

[I am currently extremely busy in Real Life (TM), sorry for not taking
this on myself].