Rollup merge of rust-lang#72777 - marmeladema:rustdoc-remove-local-def-id-from-node-id, r=petrochenkov

rustdoc: remove calls to `local_def_id_from_node_id`

rustdoc calls `local_def_id_from_node_id(CRATE_NODE_ID)` when it can just creates a top level `DefId` using `DefId::local(CRATE_DEF_INDEX)`.

cc rust-lang#50928

r? @petrochenkov

Author: RalfJung

src/librustdoc/clean/inline.rs

@@ -6,7 +6,7 @@ use rustc_ast::ast;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, DefKind, Res};
-use rustc_hir::def_id::DefId;
+use rustc_hir::def_id::{DefId, CRATE_DEF_INDEX};
 use rustc_hir::Mutability;
 use rustc_metadata::creader::LoadedMacro;
 use rustc_middle::ty;
@@ -454,11 +454,7 @@ fn build_module(cx: &DocContext<'_>, did: DefId, visited: &mut FxHashSet<DefId>)
                         name: None,
                         attrs: clean::Attributes::default(),
                         source: clean::Span::empty(),
-                        def_id: cx
-                            .tcx
-                            .hir()
-                            .local_def_id_from_node_id(ast::CRATE_NODE_ID)
-                            .to_def_id(),
+                        def_id: DefId::local(CRATE_DEF_INDEX),
                         visibility: clean::Public,
                         stability: None,
                         deprecation: None,

src/librustdoc/clean/mod.rs

@@ -1549,11 +1549,11 @@ impl<'tcx> Clean<Type> for Ty<'tcx> {
             ty::FnDef(..) | ty::FnPtr(_) => {
                 let ty = cx.tcx.lift(self).expect("FnPtr lift failed");
                 let sig = ty.fn_sig(cx.tcx);
-                let local_def_id = cx.tcx.hir().local_def_id_from_node_id(ast::CRATE_NODE_ID);
+                let def_id = DefId::local(CRATE_DEF_INDEX);
                 BareFunction(box BareFunctionDecl {
                     unsafety: sig.unsafety(),
                     generic_params: Vec::new(),
-                    decl: (local_def_id.to_def_id(), sig).clean(cx),
+                    decl: (def_id, sig).clean(cx),
                     abi: sig.abi(),
                 })
             }
@@ -2255,7 +2255,7 @@ impl Clean<Vec<Item>> for doctree::Import<'_> {
             name: None,
             attrs: self.attrs.clean(cx),
             source: self.whence.clean(cx),
-            def_id: cx.tcx.hir().local_def_id_from_node_id(ast::CRATE_NODE_ID).to_def_id(),
+            def_id: DefId::local(CRATE_DEF_INDEX),
             visibility: self.vis.clean(cx),
             stability: None,
             deprecation: None,