Remove collapsed field

`render/context` always runs after `run_global_context`, so it was always set to `true`.

This is a holdover from when rustdoc allowed configuring passes, but the `collapse-docs` pass was
removed ages ago, and the ability to configure passes is about to be removed.

src/librustdoc/html/render/context.rs

@@ -88,8 +88,6 @@ crate struct SharedContext<'tcx> {
     crate local_sources: FxHashMap<PathBuf, String>,
     /// Show the memory layout of types in the docs.
     pub(super) show_type_layout: bool,
-    /// Whether the collapsed pass ran
-    collapsed: bool,
     /// The base-URL of the issue tracker for when an item has been tagged with
     /// an issue number.
     pub(super) issue_tracker_base_url: Option<String>,
@@ -142,12 +140,6 @@ impl SharedContext<'_> {
         Ok(())
     }
 
-    /// Returns the `collapsed_doc_value` of the given item if this is the main crate, otherwise
-    /// returns the `doc_value`.
-    crate fn maybe_collapsed_doc_value<'a>(&self, item: &'a clean::Item) -> Option<String> {
-        if self.collapsed { item.collapsed_doc_value() } else { item.doc_value() }
-    }
-
     crate fn edition(&self) -> Edition {
         self.tcx.sess.edition()
     }
@@ -472,7 +464,6 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
         let (sender, receiver) = channel();
         let mut scx = SharedContext {
             tcx,
-            collapsed: krate.collapsed,
             src_root,
             local_sources,
             issue_tracker_base_url,

src/librustdoc/html/render/mod.rs

@@ -567,7 +567,7 @@ fn document_full_inner(
     is_collapsible: bool,
     heading_offset: HeadingOffset,
 ) {
-    if let Some(s) = cx.shared.maybe_collapsed_doc_value(item) {
+    if let Some(s) = item.collapsed_doc_value() {
         debug!("Doc block: =====\n{}\n=====", s);
         if is_collapsible {
             w.write_str(
@@ -1612,7 +1612,7 @@ fn render_impl(
             write!(w, "</summary>")
         }
 
-        if let Some(ref dox) = cx.shared.maybe_collapsed_doc_value(&i.impl_item) {
+        if let Some(ref dox) = i.impl_item.collapsed_doc_value() {
             let mut ids = cx.id_map.borrow_mut();
             write!(
                 w,