Rollup merge of #88810 - camelid:cleanup-pt1, r=jyn514

rustdoc: Cleanup `clean` part 1

Split out from #88379.

These commits are completely independent of each other, and each is a fairly
small change (the last few are new commits; they are not from #88379):

- Remove unnecessary `Cache.*_did` fields
- rustdoc: Get symbol for `TyParam` directly
- Create a valid `Res` in `external_path()`
- Remove unused `hir_id` parameter from `resolve_type`
- Fix redundant arguments in `external_path()`
- Remove unnecessary `is_trait` argument
- rustdoc: Cleanup a pattern match in `external_generic_args()`

r? ``@jyn514``

1 files changed, 24 insertions, 22 deletions

diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index f71660c4b2a..1f27357f6c6 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -51,6 +51,7 @@ use rustc_hir::def::CtorKind;
 use rustc_hir::def_id::DefId;
 use rustc_hir::Mutability;
 use rustc_middle::middle::stability;
+use rustc_middle::ty::TyCtxt;
 use rustc_span::symbol::{kw, sym, Symbol};
 use serde::ser::SerializeSeq;
 use serde::{Serialize, Serializer};
@@ -1067,13 +1068,13 @@ fn render_assoc_items(
         return;
     }
     if !traits.is_empty() {
-        let deref_impl = traits
-            .iter()
-            .find(|t| t.inner_impl().trait_.def_id_full(cache) == cache.deref_trait_did);
+        let deref_impl = traits.iter().find(|t| {
+            t.inner_impl().trait_.def_id_full(cache) == cx.tcx().lang_items().deref_trait()
+        });
         if let Some(impl_) = deref_impl {
-            let has_deref_mut = traits
-                .iter()
-                .any(|t| t.inner_impl().trait_.def_id_full(cache) == cache.deref_mut_trait_did);
+            let has_deref_mut = traits.iter().any(|t| {
+                t.inner_impl().trait_.def_id_full(cache) == cx.tcx().lang_items().deref_mut_trait()
+            });
             render_deref_methods(w, cx, impl_, containing_item, has_deref_mut);
         }
         let (synthetic, concrete): (Vec<&&Impl>, Vec<&&Impl>) =
@@ -1163,7 +1164,7 @@ fn render_deref_methods(
     }
 }
 
-fn should_render_item(item: &clean::Item, deref_mut_: bool, cache: &Cache) -> bool {
+fn should_render_item(item: &clean::Item, deref_mut_: bool, tcx: TyCtxt<'_>) -> bool {
     let self_type_opt = match *item.kind {
         clean::MethodItem(ref method, _) => method.decl.self_type(),
         clean::TyMethodItem(ref method) => method.decl.self_type(),
@@ -1177,7 +1178,7 @@ fn should_render_item(item: &clean::Item, deref_mut_: bool, cache: &Cache) -> bo
                 (mutability == Mutability::Mut, false, false)
             }
             SelfTy::SelfExplicit(clean::ResolvedPath { did, .. }) => {
-                (false, Some(did) == cache.owned_box_did, false)
+                (false, Some(did) == tcx.lang_items().owned_box(), false)
             }
             SelfTy::SelfValue => (false, false, true),
             _ => (false, false, false),
@@ -1300,7 +1301,7 @@ fn render_impl(
             && match render_mode {
                 RenderMode::Normal => true,
                 RenderMode::ForDeref { mut_: deref_mut_ } => {
-                    should_render_item(&item, deref_mut_, cx.cache())
+                    should_render_item(&item, deref_mut_, cx.tcx())
                 }
             };
 
@@ -1798,13 +1799,13 @@ fn get_methods(
     for_deref: bool,
     used_links: &mut FxHashSet<String>,
     deref_mut: bool,
-    cache: &Cache,
+    tcx: TyCtxt<'_>,
 ) -> Vec<String> {
     i.items
         .iter()
         .filter_map(|item| match item.name {
             Some(ref name) if !name.is_empty() && item.is_method() => {
-                if !for_deref || should_render_item(item, deref_mut, cache) {
+                if !for_deref || should_render_item(item, deref_mut, tcx) {
                     Some(format!(
                         "<a href=\"#{}\">{}</a>",
                         get_next_url(used_links, format!("method.{}", name)),
@@ -1866,7 +1867,9 @@ fn sidebar_assoc_items(cx: &Context<'_>, out: &mut Buffer, it: &clean::Item) {
             let mut ret = v
                 .iter()
                 .filter(|i| i.inner_impl().trait_.is_none())
-                .flat_map(move |i| get_methods(i.inner_impl(), false, used_links_bor, false, cache))
+                .flat_map(move |i| {
+                    get_methods(i.inner_impl(), false, used_links_bor, false, cx.tcx())
+                })
                 .collect::<Vec<_>>();
             if !ret.is_empty() {
                 // We want links' order to be reproducible so we don't use unstable sort.
@@ -1884,11 +1887,9 @@ fn sidebar_assoc_items(cx: &Context<'_>, out: &mut Buffer, it: &clean::Item) {
         }
 
         if v.iter().any(|i| i.inner_impl().trait_.is_some()) {
-            if let Some(impl_) = v
-                .iter()
-                .filter(|i| i.inner_impl().trait_.is_some())
-                .find(|i| i.inner_impl().trait_.def_id_full(cache) == cache.deref_trait_did)
-            {
+            if let Some(impl_) = v.iter().filter(|i| i.inner_impl().trait_.is_some()).find(|i| {
+                i.inner_impl().trait_.def_id_full(cache) == cx.tcx().lang_items().deref_trait()
+            }) {
                 sidebar_deref_methods(cx, out, impl_, v);
             }
 
@@ -1986,10 +1987,9 @@ fn sidebar_deref_methods(cx: &Context<'_>, out: &mut Buffer, impl_: &Impl, v: &V
                 }
             }
         }
-        let deref_mut = v
-            .iter()
-            .filter(|i| i.inner_impl().trait_.is_some())
-            .any(|i| i.inner_impl().trait_.def_id_full(c) == c.deref_mut_trait_did);
+        let deref_mut = v.iter().filter(|i| i.inner_impl().trait_.is_some()).any(|i| {
+            i.inner_impl().trait_.def_id_full(c) == cx.tcx().lang_items().deref_mut_trait()
+        });
         let inner_impl = target
             .def_id_full(c)
             .or_else(|| {
@@ -2002,7 +2002,9 @@ fn sidebar_deref_methods(cx: &Context<'_>, out: &mut Buffer, impl_: &Impl, v: &V
             let mut ret = impls
                 .iter()
                 .filter(|i| i.inner_impl().trait_.is_none())
-                .flat_map(|i| get_methods(i.inner_impl(), true, &mut used_links, deref_mut, c))
+                .flat_map(|i| {
+                    get_methods(i.inner_impl(), true, &mut used_links, deref_mut, cx.tcx())
+                })
                 .collect::<Vec<_>>();
             if !ret.is_empty() {
                 write!(