SVN r305382 breaks world32 on amd64 (and native 32-bit)

[Bruce Evans]

On Sun, 4 Sep 2016, Michael Butler wrote:

> Build fails with:
>
> ===> lib/msun (obj,all,install)
> Building /usr/obj/usr/src/lib/msun/e_fmodf.o
> /usr/src/lib/msun/i387/e_fmodf.S:10:17: error: register %rsp is only
> available in 64-bit mode
> movss %xmm0,-4(%rsp)
>                ^~~~
> /usr/src/lib/msun/i387/e_fmodf.S:11:17: error: register %rsp is only

Fixed.  I noticed it proof-reading the committed sources instead of
the commit mail, and missed it for a while since I checked amd64 first.

The bug was there for a couple of hours.  At least the build failure
prevented it being run.

Bruce