Auto merge of #1703 - calebzulawski:master, r=RalfJung

Remove non-power-of-two SIMD vectors

Closes rust-lang/rust#81868.

Author: bors

rust-version

@@ -1 +1 @@
-6a388dcfbb07b3ca3d4ad3fd3902ac7e3b11b5f6
+bb587b1a1737738658d2eaecd4c8c1cab555257a

tests/run-pass/simd-intrinsic-generic-elements.rs

@@ -7,10 +7,6 @@ struct i32x2(i32, i32);
 #[repr(simd)]
 #[derive(Copy, Clone, Debug, PartialEq)]
 #[allow(non_camel_case_types)]
-struct i32x3(i32, i32, i32);
-#[repr(simd)]
-#[derive(Copy, Clone, Debug, PartialEq)]
-#[allow(non_camel_case_types)]
 struct i32x4(i32, i32, i32, i32);
 #[repr(simd)]
 #[derive(Copy, Clone, Debug, PartialEq)]
@@ -20,12 +16,10 @@ struct i32x8(i32, i32, i32, i32,
 
 fn main() {
     let _x2 = i32x2(20, 21);
-    let _x3 = i32x3(30, 31, 32);
     let _x4 = i32x4(40, 41, 42, 43);
     let _x8 = i32x8(80, 81, 82, 83, 84, 85, 86, 87);
 
     let _y2 = i32x2(120, 121);
-    let _y3 = i32x3(130, 131, 132);
     let _y4 = i32x4(140, 141, 142, 143);
     let _y8 = i32x8(180, 181, 182, 183, 184, 185, 186, 187);