Fix query docs

They were not formatted correctly, so rustdoc was interpreting some
parts as code. Also cleaned up some other query docs that weren't
causing issues, but were formatted incorrectly.

compiler/rustc_middle/src/query/mod.rs

@@ -92,7 +92,7 @@ rustc_queries! {
         /// Computes the `DefId` of the corresponding const parameter in case the `key` is a
         /// const argument and returns `None` otherwise.
         ///
-        /// ```rust
+        /// ```ignore (incomplete)
         /// let a = foo::<7>();
         /// //            ^ Calling `opt_const_param_of` for this argument,
         ///
@@ -162,10 +162,12 @@ rustc_queries! {
         /// Specifically this is the bounds written on the trait's type
         /// definition, or those after the `impl` keyword
         ///
+        /// ```ignore (incomplete)
         /// type X: Bound + 'lt
-        ///         ^^^^^^^^^^^
+        /// //      ^^^^^^^^^^^
         /// impl Debug + Display
-        ///      ^^^^^^^^^^^^^^^
+        /// //   ^^^^^^^^^^^^^^^
+        /// ```
         ///
         /// `key` is the `DefId` of the associated type or opaque type.
         ///
@@ -176,18 +178,22 @@ rustc_queries! {
 
         /// Elaborated version of the predicates from `explicit_item_bounds`.
         ///
-        /// Example for
+        /// For example:
         ///
+        /// ```
         /// trait MyTrait {
-        ///     type MyAType: Eq + ?Sized`
+        ///     type MyAType: Eq + ?Sized;
         /// }
+        /// ```
         ///
         /// `explicit_item_bounds` returns `[<Self as MyTrait>::MyAType: Eq]`,
         /// and `item_bounds` returns
+        /// ```text
         /// [
         ///     <Self as Trait>::MyAType: Eq,
         ///     <Self as Trait>::MyAType: PartialEq<<Self as Trait>::MyAType>
         /// ]
+        /// ```
         ///
         /// Bounds from the parent (e.g. with nested impl trait) are not included.
         query item_bounds(key: DefId) -> &'tcx ty::List<ty::Predicate<'tcx>> {