Set up docs for missing core types

Fixes #22085

src/libcore/lib.rs

@@ -141,6 +141,10 @@ pub mod hash;
 pub mod fmt;
 pub mod error;
 
+#[doc(primitive = "bool")]
+mod bool {
+}
+
 // note: does not need to be public
 mod tuple;
 mod array;

src/libcore/tuple.rs

@@ -34,6 +34,7 @@
 //! * `Default`
 
 #![stable(feature = "rust1", since = "1.0.0")]
+#![doc(primitive = "tuple")]
 
 use clone::Clone;
 use cmp::*;