Restore details for Impls on Foreign Types

These were previously removed along with the details in the
"Implementors" section of trait pages. But for "Implementations on
Foreign Types," we need to include the details because they will not be
documented anywhere else.

Author: jsha

src/librustdoc/html/render/print_item.rs

@@ -15,11 +15,12 @@ use rustc_span::symbol::{kw, sym, Symbol};
 use super::{
     collect_paths_for_type, document, ensure_trailing_slash, item_ty_to_strs, notable_traits_decl,
     render_assoc_item, render_assoc_items, render_attributes_in_code, render_attributes_in_pre,
-    render_impl_summary, render_stability_since_raw, write_srclink, AssocItemLink, Context,
+    render_impl, render_impl_summary, render_stability_since_raw, write_srclink, AssocItemLink,
+    Context,
 };
 use crate::clean::{self, GetDefId};
 use crate::formats::item_type::ItemType;
-use crate::formats::{AssocItemRender, Impl};
+use crate::formats::{AssocItemRender, Impl, RenderMode};
 use crate::html::escape::Escape;
 use crate::html::format::{print_abi_with_space, print_where_clause, Buffer, PrintWithSpace};
 use crate::html::highlight;
@@ -694,15 +695,20 @@ fn item_trait(w: &mut Buffer, cx: &Context<'_>, it: &clean::Item, t: &clean::Tra
             write_small_section_header(w, "foreign-impls", "Implementations on Foreign Types", "");
 
             for implementor in foreign {
-                render_impl_summary(
+                let provided_methods = implementor.inner_impl().provided_trait_methods(cx.tcx());
+                let assoc_link =
+                    AssocItemLink::GotoSource(implementor.impl_item.def_id, &provided_methods);
+                render_impl(
                     w,
                     cx,
                     &implementor,
                     it,
-                    &implementor.impl_item,
+                    assoc_link,
+                    RenderMode::Normal,
                     false,
                     None,
                     true,
+                    false,
                     &[],
                 );
             }