Fixing sparc ceil/floor/trunc implementations

[David Miller]

From: Aurelien Jarno <aurelien@aurel32.net>
Date: Wed, 27 Jul 2016 13:20:51 +0200

> Coming back about the fix saving and restoring the FSR, it appears
> it has a big impact as expected. In that case the C implementation is
> always faster than the fixed implementations.
> 
> I would therefore thing that a way to fix the issue without affecting
> too much the performances is to remove the sparc specific
> implementations.

No objections.  We can resurrect the sparc specific assembler from the
repo is we ever want to try and make them work properly again.

> For the sparc64 case where the floating points arguments are passed
> through floating point registers, it might make sense to compile the
> C implementation using VIS3 to benefit from the movdtox/movxtod and
> movwtos/movstow instructions.

That shouldn't be too hard to do with multiarch.