Auto merge of #49141 - gnzlbg:simd_select, r=alexcrichton

adds simd_select intrinsic

The select SIMD intrinsic is used to select elements from two SIMD vectors using a mask:

```rust
let mask = b8x4::new(true, false, false, true);
let a = f32x4::new(1., 2., 3., 4.);
let b = f32x4::new(5., 6., 7., 8.);
assert_eq!(simd_select(mask, a, b), f32x4::new(1., 6., 7., 4.));
```

The number of lanes between the mask and the vectors must match, but the vector width of the mask does not need to match that of the vectors. The mask is required to be a vector of signed integers.

Note: this intrinsic will be exposed via `std::simd`'s vector masks - users are not expected to use it directly.

0 files changed, 0 insertions, 0 deletions