use the right feature in codegen tests

Author: folkertdev

tests/codegen/issues/issue-84268.rs

@@ -1,5 +1,5 @@
 //@ compile-flags: -Copt-level=3 --crate-type=rlib
-#![feature(intrinsics, repr_simd)]
+#![feature(core_intrinsics, repr_simd)]
 
 use std::intrinsics::simd::{simd_eq, simd_fabs};
 

tests/codegen/simd/simd_arith_offset.rs

@@ -3,7 +3,7 @@
 //
 
 #![crate_type = "lib"]
-#![feature(repr_simd, intrinsics)]
+#![feature(repr_simd, core_intrinsics)]
 
 use std::intrinsics::simd::simd_arith_offset;