ICE when using ADX intrinsics on nightly

[jethrogb]

unsafe fn add_1_2_3() -> u32{
    let mut out = 0;
    std::arch::x86_64::_addcarryx_u32(1, 2, 3, &mut out);
    out
}

fn main() {
    if is_x86_feature_detected!("adx") {
        println!("{}", unsafe { add_1_2_3() });
    }
}

$ rustc +nightly --version
rustc 1.34.0-nightly (d8a0dd7ae 2019-01-28)
$ rustc +nightly adx.rs
Invalid bitcast
i32* bitcast (void <badref> to i32*)
Referencing global in another module!
i32* bitcast (void <badref> to i32*)
; ModuleID = 'feat.7rcbfp3g-cgu.2'
void <badref>
; ModuleID = 'Segmentation fault (core dumped)

Regression from beta to nightly

[jethrogb]

This might be #57993 / rust-lang/stdarch#661

[jonas-schievink]

No longer reproduces, marking as needstest.

[gnzlbg]

We have added a test for this in stdsimd.

[jonas-schievink]

Great! In that case, closing.