[Patch, fortran] PR30084 - segmentation falut when compiling certain code

[Paul Thomas]

Steve,
> OK with your typo fixes and the fix to nested_modules_6.f90.
>
>   
Many thanks!  I am just now working on the last three readily fixable 
PRs in the interface meta-bug PR29670.  I'd like to get them done befoe 
Christmas Eve.

Paul