[smooth] Fix compilation for x86_32.x86 ABI

The code assumed that if __SSE2__ is defined, then 64-bit
integer types are available. This is not the case apparently
for certain multilib compiler targets like x86_32.x86 used
by Gentoo.

This patch fixes the issue by disabling the special code
path when 64-bit integer types are not available.

1 file changed