Auto merge of #87234 - cjgillot:lower-mono, r=petrochenkov

Lower only one HIR owner at a time

Based on https://github.com/rust-lang/rust/pull/83723
Additional diff is here: https://github.com/cjgillot/rust/compare/ownernode...lower-mono

Lowering is very tangled and has a tendency to intertwine the transformation of different items. This PR aims at simplifying the logic by:
- moving global analyses to the resolver (item_generics_num_lifetimes, proc_macros, trait_impls);
- removing a few special cases (non-exported macros and use statements);
- restricting the amount of available information at any one time;
- avoiding back-and-forth between different owners: an item must now be lowered all at once, and its parent cannot refer to its nodes.

I also removed the sorting of bodies by span.  The diagnostic ordering changes marginally, since definitions are pretty much sorted already according to the AST. This uncovered a subtlety in thir-unsafeck.

(While these items could logically be in different PRs, the dependency between commits and the amount of conflicts force a monolithic PR.)

3 files changed, 12 insertions, 8 deletions

diff --git a/src/test/incremental/hashes/extern_mods.rs b/src/test/incremental/hashes/extern_mods.rs
index 783407a9e04..4bc98fd7cd0 100644
--- a/src/test/incremental/hashes/extern_mods.rs
+++ b/src/test/incremental/hashes/extern_mods.rs
@@ -143,13 +143,13 @@ extern "rust-call" {
 // Make function public --------------------------------------------------------
 #[cfg(any(cfail1,cfail4))]
 extern "C" {
-    fn make_function_public(c: i32);
+    fn     make_function_public(c: i32);
 }
 
 #[cfg(not(any(cfail1,cfail4)))]
-#[rustc_clean(cfg = "cfail2", except = "hir_owner")]
+#[rustc_clean(cfg = "cfail2")]
 #[rustc_clean(cfg = "cfail3")]
-#[rustc_clean(cfg = "cfail5", except = "hir_owner")]
+#[rustc_clean(cfg = "cfail5")]
 #[rustc_clean(cfg = "cfail6")]
 extern "C" {
     pub fn make_function_public(c: i32);
diff --git a/src/test/incremental/hashes/inherent_impls.rs b/src/test/incremental/hashes/inherent_impls.rs
index d711cc20dd7..3a59377e819 100644
--- a/src/test/incremental/hashes/inherent_impls.rs
+++ b/src/test/incremental/hashes/inherent_impls.rs
@@ -116,20 +116,24 @@ impl Foo {
 // Change Method Privacy -------------------------------------------------------
 #[cfg(any(cfail1,cfail4))]
 impl Foo {
+    //------------------------------------------------------------------------------
+    //--------------------------
+    //------------------------------------------------------------------------------
+    //--------------------------
     pub fn method_privacy() { }
 }
 
 #[cfg(not(any(cfail1,cfail4)))]
-#[rustc_clean(cfg="cfail2", except="hir_owner")]
+#[rustc_clean(cfg="cfail2")]
 #[rustc_clean(cfg="cfail3")]
-#[rustc_clean(cfg="cfail5", except="hir_owner")]
+#[rustc_clean(cfg="cfail5")]
 #[rustc_clean(cfg="cfail6")]
 impl Foo {
     #[rustc_clean(cfg="cfail2", except="associated_item,hir_owner,hir_owner_nodes")]
     #[rustc_clean(cfg="cfail3")]
-    #[rustc_clean(cfg="cfail5", except="associated_item,hir_owner,hir_owner_nodes,optimized_mir")]
+    #[rustc_clean(cfg="cfail5", except="associated_item,hir_owner,hir_owner_nodes")]
     #[rustc_clean(cfg="cfail6")]
-    fn method_privacy() { }
+    fn     method_privacy() { }
 }
 
 // Change Method Selfness -----------------------------------------------------------
diff --git a/src/tools/clippy/clippy_lints/src/fallible_impl_from.rs b/src/tools/clippy/clippy_lints/src/fallible_impl_from.rs
index 7e4d1b3ef9f..f22f52b949e 100644
--- a/src/tools/clippy/clippy_lints/src/fallible_impl_from.rs
+++ b/src/tools/clippy/clippy_lints/src/fallible_impl_from.rs
@@ -65,7 +65,7 @@ impl<'tcx> LateLintPass<'tcx> for FallibleImplFrom {
     }
 }
 
-fn lint_impl_body<'tcx>(cx: &LateContext<'tcx>, impl_span: Span, impl_items: &[hir::ImplItemRef<'_>]) {
+fn lint_impl_body<'tcx>(cx: &LateContext<'tcx>, impl_span: Span, impl_items: &[hir::ImplItemRef]) {
     use rustc_hir::intravisit::{self, NestedVisitorMap, Visitor};
     use rustc_hir::{Expr, ExprKind, ImplItemKind, QPath};