[RFC] ARM Floating point defaults

[Paul Brook]

It appears that gcc and gas use different defaults for hardware floating point 
flags. On linux and netbsd targets the default is overridden, so everything 
is ok.

On other targets[1] gcc defaults to soft-float fpa, but gas defaults to 
whatever hardware is supported by the CPU.

This causes a couple of problems:
- Objects are marked as hard-float by default.
- Code compiled for armv5 chips are marked as VFP format float.
Both of these cause linker errors when objects compiled with default options 
(eg. libc) are mixed with objects compiled with explicitly specified options.

Would it be acceptable to change the gas defaults to match those used by gcc?

At the same time, add a linker option that allows linking of objects with 
incompatible flags. This would allow the user to override the checks when 
linking old objects with incorrect flags.

Paul

[1] The only other gcc target which doesn't default to soft-float is 
arm-semi-aof, which doesn't isn't supported by gas.