[cairo] Speeding up _cairo_fixed_from_double

[Vladimir Vukicevic]

Daniel Amelang wrote:
>> Keep in mind that configure-time endian checks are unreliable on
>> Mac OS X because a single executable may contain objects for multiple
>> architectures (right now 32+64 bit Intel and PPC)...
> 
> AFAIK, the existence of fat binaries doesn't interfere with autoconf's
> job. We're not building fat binaries during the configure stage, and
> we don't compile to a fat binary. In addition, that would be a general
> autoconf on OS X issue, not a cairo thing.
> 
> But thanks for the heads up, I could be wrong.

Anyone who's building a fat binary effectively needs to go through a 
build twice -- including the full configure stage, once for each arch & 
SDK.  If someone has this optimized down to just doing a single build 
that builds both at the same time, great, but then making sure this case 
works is on their shoulders.  With a compile-time endian check, cairo 
will compile and run correctly when built for either the x86 or the ppc 
architecture, and that's all that's required for universal binaries.

     - Vlad