[FORTRAN, fix PR30478] Slightly overhaul ENUM parsing

[FX Coudert]

> Other than the above I think the patch is ok.  You may want to
> see if FX has any comments.

I was going to say that the patch looks OK to me (actually, I cheated  
a bit and read previous versions of it in the PR), although it  
doesn't apply *at all* to mainline :)


On another note, I have a call to arms: we are getting a backlog of  
un-backported patches, applied to 4.3 but not to earlier branches. I  
think that we should at least backport all possible patches to 4.2,  
as time permit.

FX