Remove double spaces after dots in comments

compiler/rustc_hir/src/hir.rs

@@ -94,7 +94,7 @@ pub enum LifetimeName {
     /// Implicit lifetime in a context like `dyn Foo`. This is
     /// distinguished from implicit lifetimes elsewhere because the
     /// lifetime that they default to must appear elsewhere within the
-    /// enclosing type.  This means that, in an `impl Trait` context, we
+    /// enclosing type. This means that, in an `impl Trait` context, we
     /// don't have to create a parameter for them. That is, `impl
     /// Trait<Item = &u32>` expands to an opaque type like `type
     /// Foo<'a> = impl Trait<Item = &'a u32>`, but `impl Trait<item =
@@ -826,7 +826,7 @@ pub struct OwnerNodes<'tcx> {
     pub hash_without_bodies: Fingerprint,
     /// Full HIR for the current owner.
     // The zeroth node's parent should never be accessed: the owner's parent is computed by the
-    // hir_owner_parent query.  It is set to `ItemLocalId::INVALID` to force an ICE if accidentally
+    // hir_owner_parent query. It is set to `ItemLocalId::INVALID` to force an ICE if accidentally
     // used.
     pub nodes: IndexVec<ItemLocalId, Option<ParentedNode<'tcx>>>,
     /// Content of local bodies.