Move some methods from tcx.hir() to tcx

Renamings:
- find -> opt_hir_node
- get -> hir_node
- find_by_def_id -> opt_hir_node_by_def_id
- get_by_def_id -> hir_node_by_def_id

Fix rebase changes using removed methods

Use `tcx.hir_node_by_def_id()` whenever possible in compiler

Fix clippy errors

Fix compiler

Apply suggestions from code review

Co-authored-by: Vadim Petrochenkov <[email protected]>

Add FIXME for `tcx.hir()` returned type about its removal

Simplify with with `tcx.hir_node_by_def_id`

Author: zetanumbers

src/bin/miri.rs

@@ -144,7 +144,7 @@ impl rustc_driver::Callbacks for MiriBeRustCompilerCalls {
                             // Otherwise it may cause unexpected behaviours and ICEs
                             // (https://github.com/rust-lang/rust/issues/86261).
                             let is_reachable_non_generic = matches!(
-                                tcx.hir().get(tcx.local_def_id_to_hir_id(local_def_id)),
+                                tcx.hir_node_by_def_id(local_def_id),
                                 Node::Item(&hir::Item {
                                     kind: hir::ItemKind::Static(..) | hir::ItemKind::Fn(..),
                                     ..