[gfortran,patch] PR fortran/28163: Don't call library function for string copying

[FX Coudert]

> I'm curious if this should be selectable via something like
> -minline-all-stringops resp. -f{no-}builtin-whatever?
> 
> While it may give a nice performance boost, it most likely is something
> e.g. -Os doesn't like, fwiw.

You're right about -Os, though I don't think it needs an option all for 
itself. Also, we probably won't be inlining all string operations, 
because some would be a real pain to maintain if they were inside the 
front-end.

What about simply call the library version if -Os is specified, i.e. 
make the new code conditional on optimize_size? Would that seem acceptable?

Thanks,
FX