[PATCH] ARM: Use libc calls for fenv functions

[Wilco]

> Joseph Myers wrote:
> On Fri, 23 May 2014, Wilco wrote:
> 
> > Hi,
> >
> > This patch uses libc calls defined by fenv_private.h to implement
> > several fenv functions rather than duplicating functionality. To make
> > this work for softfp builds, ensure functions in fenv_private are not
> > conditionally compiled.
> >
> > OK for commit?
> 
> OK, if tested for both hard and soft float builds.

I built with CFLAGS="-mfloat-abi=soft". This builds the objects but won't link
as ld assumes hardfp abi despite the object saying otherwise, so it doesn't 
appear these options are well supported in GCC. I checked disassembly of 
a few fenv functions and sin, and they look correct (ie. there is always the
features test before FPSCR is accessed).

Marcus can you check in?

Wilco