Tweak a few items in the docs

Author: alexcrichton

crates/core_arch/src/mod.rs

@@ -88,7 +88,7 @@ pub mod arch {
     ///
     /// ## SIMD
     ///
-    /// The [simd proposa][simd] for WebAssembly adds a new `v128` type for a
+    /// The [simd proposal][simd] for WebAssembly adds a new `v128` type for a
     /// 128-bit SIMD register. It also adds a large array of instructions to
     /// operate on the `v128` type to perform data processing. The SIMD proposal
     /// has been in progress for quite some time and many instructions have come

crates/core_arch/src/wasm32/simd128.rs

@@ -410,11 +410,13 @@ pub macro v8x16_shuffle(
 
 // internal implementation detail of the `v8x16_shuffle`, done so there's a name
 // that always works for the macro to import.
+#[doc(hidden)]
 pub use crate::mem::transmute as __v8x16_shuffle_transmute;
 
 // internal to this module and only generated here as an implementation detail
 // of the `v8x16_shuffle` macro.
 #[repr(simd)]
+#[doc(hidden)]
 pub struct __v8x16_shuffle_u8x16(
     u8,
     u8,