Auto merge of #118853 - calebzulawski:simd-intrinsics, r=RalfJung

Add core::intrinsics::simd

Intended to close rust-lang/portable-simd#381.

r? ralfjung

Author: bors

library/core/src/intrinsics.rs

@@ -59,6 +59,7 @@ use crate::marker::Tuple;
 use crate::mem;
 
 pub mod mir;
+pub mod simd;
 
 // These imports are used for simplifying intra-doc links
 #[allow(unused_imports)]