auxilary/os: Add Solaris support in os_get_total_physical_memory.

The patch fixes the build on Oracle Solaris.

  CC     os/os_misc.lo
"os/os_misc.c", line 59: #error: unexpected platform in os_sysinfo.c

Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
vc4: Clear padding of ioctl arguments.

Fixes valgrind complaints from valgrind being unaware of our ioctls.
vc4: Fix save/restore of the VS/FS in the blitter.

When I made the shader cache take the .fs member and moved the binding
point to .bind_fs, I failed to update these.  Fixes crashes in
copyteximage-related tests.