Remove remaining uses of #[rustc_args_required_const] (#1113)

Author: Amanieu

crates/core_arch/src/simd_llvm.rs

@@ -9,19 +9,12 @@ extern "platform-intrinsic" {
     pub fn simd_gt<T, U>(x: T, y: T) -> U;
     pub fn simd_ge<T, U>(x: T, y: T) -> U;
 
-    #[rustc_args_required_const(2)]
     pub fn simd_shuffle2<T, U>(x: T, y: T, idx: [u32; 2]) -> U;
-    #[rustc_args_required_const(2)]
     pub fn simd_shuffle4<T, U>(x: T, y: T, idx: [u32; 4]) -> U;
-    #[rustc_args_required_const(2)]
     pub fn simd_shuffle8<T, U>(x: T, y: T, idx: [u32; 8]) -> U;
-    #[rustc_args_required_const(2)]
     pub fn simd_shuffle16<T, U>(x: T, y: T, idx: [u32; 16]) -> U;
-    #[rustc_args_required_const(2)]
     pub fn simd_shuffle32<T, U>(x: T, y: T, idx: [u32; 32]) -> U;
-    #[rustc_args_required_const(2)]
     pub fn simd_shuffle64<T, U>(x: T, y: T, idx: [u32; 64]) -> U;
-    #[rustc_args_required_const(2)]
     pub fn simd_shuffle128<T, U>(x: T, y: T, idx: [u32; 128]) -> U;
 
     #[rustc_const_unstable(feature = "const_simd_insert", issue = "none")]