Why do -ffixed-line-length and -free... use - instead of =?

[Brooks Moses]

For essentially all of the GFortran command-line options that have 
numerical parameters, the syntax is

   -foption-name=<value>

However, for -ffixed-line-length and -ffree-line-length, the syntax is

   -ffixed-line-length-<value>

where the value is separated by a - instead of an =.  This is confusing 
and hard to remember.

Is there some reason that this is this way, other than the fact that 
it's been this way for a while?

If there's no particular reason why it's this way, I propose changing 
the current syntax to an undocumented option, and adding a new 
(documented) form of the option that uses an "=".  That way, we're not 
gratuitously breaking any makefiles that use the current form, but we 
can still document it only in the form that's consistent with everything 
else.

Comments?  I'll write up a patch, if this seems like a good idea.

- Brooks