Revert "attr/passes: comment -> doc comment"

This reverts commit 6f0b8f1.

Author: davidtwco

Diff for: compiler/rustc_attr/src/builtin.rs

@@ -135,22 +135,9 @@ impl ConstStability {
 #[derive(Encodable, Decodable, PartialEq, Copy, Clone, Debug, Eq, Hash)]
 #[derive(HashStable_Generic)]
 pub enum StabilityLevel {
-    /// `#[unstable]`
-    Unstable {
-        /// Reason for the current stability level.
-        reason: UnstableReason,
-        /// Relevant `rust-lang/rust` issue.
-        issue: Option<NonZeroU32>,
-        is_soft: bool,
-    },
-    /// `#[stable]`
-    Stable {
-        /// Rust release which stabilized this feature.
-        since: Symbol,
-        /// Is this item allowed to be referred to on stable, despite being contained in unstable
-        /// modules?
-        allowed_through_unstable_modules: bool,
-    },
+    // Reason for the current stability level and the relevant rust-lang issue
+    Unstable { reason: UnstableReason, issue: Option<NonZeroU32>, is_soft: bool },
+    Stable { since: Symbol, allowed_through_unstable_modules: bool },
 }
 
 impl StabilityLevel {

Diff for: compiler/rustc_passes/src/lib_features.rs

@@ -1,8 +1,8 @@
-//! Detecting lib features (i.e., features that are not lang features).
-//!
-//! These are declared using stability attributes (e.g., `#[stable (..)]` and `#[unstable (..)]`),
-//! but are not declared in one single location (unlike lang features), which means we need to
-//! collect them instead.
+// Detecting lib features (i.e., features that are not lang features).
+//
+// These are declared using stability attributes (e.g., `#[stable (..)]`
+// and `#[unstable (..)]`), but are not declared in one single location
+// (unlike lang features), which means we need to collect them instead.
 
 use rustc_ast::{Attribute, MetaItemKind};
 use rustc_errors::struct_span_err;

Diff for: compiler/rustc_passes/src/stability.rs

@@ -29,13 +29,13 @@ use std::num::NonZeroU32;
 
 #[derive(PartialEq)]
 enum AnnotationKind {
-    /// Annotation is required if not inherited from unstable parents.
+    // Annotation is required if not inherited from unstable parents
     Required,
-    /// Annotation is useless, reject it.
+    // Annotation is useless, reject it
     Prohibited,
-    /// Deprecation annotation is useless, reject it. (Stability attribute is still required.)
+    // Deprecation annotation is useless, reject it. (Stability attribute is still required.)
     DeprecationProhibited,
-    /// Annotation itself is useless, but it can be propagated to children.
+    // Annotation itself is useless, but it can be propagated to children
     Container,
 }
 
@@ -83,7 +83,7 @@ impl InheritStability {
     }
 }
 
-/// A private tree-walker for producing an `Index`.
+// A private tree-walker for producing an Index.
 struct Annotator<'a, 'tcx> {
     tcx: TyCtxt<'tcx>,
     index: &'a mut Index,
@@ -94,9 +94,9 @@ struct Annotator<'a, 'tcx> {
 }
 
 impl<'a, 'tcx> Annotator<'a, 'tcx> {
-    /// Determine the stability for a node based on its attributes and inherited stability. The
-    /// stability is recorded in the index and used as the parent. If the node is a function,
-    /// `fn_sig` is its signature.
+    // Determine the stability for a node based on its attributes and inherited
+    // stability. The stability is recorded in the index and used as the parent.
+    // If the node is a function, `fn_sig` is its signature
     fn annotate<F>(
         &mut self,
         def_id: LocalDefId,