Constant core::arch::x86::_MM_FROUND_TRUNC

pub const _MM_FROUND_TRUNC: i32 = _MM_FROUND_RAISE_EXC | _MM_FROUND_TO_ZERO; // 3i32

This is supported on (non-crate feature miri-test-libstd or test or doctest) and x86 only.

truncate and do not suppress exceptions