[fortran] Disable use of -malign-double

[Tobias Schlüter]

Andrew Pinski wrote:
> So that is their problem, when stuff does not work and they
> use an option which changes the ABI, then they get what they
> deserve.  Really we should not have these options but for somereason in the
> past, people thought it was a good idea to expose stuff like this.

I don't think we can assume that our users know what an "ABI" is.  They 
read the documentation, read "faster code", and since they compile all 
their code themselves(*) they don't worry, about the part where it says 
that it may not work to combine code that is in part compiled with 
-malign-double and in part not.

If it's at all possible the right fix would be to make sure that library 
calls don't depend on whether the user explicitly gave -malign-double or 
not.  For the time being, I agree with Steve that -malign-error should 
give a hard error iff it's not the system's default.

 > Also by the way I could compile all of the libraries with 
-malign-double and have the option
 > work correctly so erroring out is wrong.

Then -malign-double is the default for your system, and using it would 
indeed not constitute an error.

- Tobi

(*) from the user POV.  After all, unlike C the user interface for 
runtime library functions in Fortran is nothing like the user interface 
for functions from user code.  So the runtime library is much more a 
part of the compiler than in C, where in fact it is usually provided by 
the system, not the compiler.