[Patch, fortran] PR24558, PR20877 and PR25047 - module function alternate entries.

[Paul Thomas]

tobi,

>
> I think yes with the change we discussed before, but I'm not sure I  
> understand what the change to resolve_entries really does.  How can 
> we  end up there with the wrong namespace?

This comes back to the original problem:  Unlike a subroutine entry, the 
function entry can have references that appear before the entry 
statement.  The fix proceeds by leaving the symtree in the function 
namespace, as if this were an external, rather than a module function.  
This results in a usable, in the module sense, symbol that is completely 
resolved.  However, the fake return value mechanism is broken at this 
stage because the ns field has not been fixed up.  This is what the 
change to resolve_entries does.

I did start work on this patch, before Christmas, by removing the 
symtree from the function namespace and putting it in the module 
namespace.  This got very messy and there were considerably more fixes 
needed down-stream.  There was a light bulb moment a couple of weeks 
back, when I realised that I must be able to get it to work like an 
external function.  This slightly awkward fix with the namespace is the 
price paid for simplicity elsewhere.

I will await your final OK before committing.

Thanks

Paul