Remove AssignDesugar span

compiler/rustc_ast_lowering/src/expr.rs

@@ -1242,13 +1242,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let rhs = self.lower_expr(rhs);
 
         // Introduce a `let` for destructuring: `let (lhs1, lhs2) = t`.
-        let destructure_let = self.stmt_let_pat(
-            None,
-            whole_span,
-            Some(rhs),
-            pat,
-            hir::LocalSource::AssignDesugar(self.lower_span(eq_sign_span)),
-        );
+        let destructure_let =
+            self.stmt_let_pat(None, whole_span, Some(rhs), pat, hir::LocalSource::AssignDesugar);
 
         // `a = lhs1; b = lhs2;`.
         let stmts = self.arena.alloc_from_iter(std::iter::once(destructure_let).chain(assignments));

compiler/rustc_hir/src/hir.rs

@@ -2975,8 +2975,7 @@ pub enum LocalSource {
     /// A desugared `<expr>.await`.
     AwaitDesugar,
     /// A desugared `expr = expr`, where the LHS is a tuple, struct, array or underscore expression.
-    /// The span is that of the `=` sign.
-    AssignDesugar(Span),
+    AssignDesugar,
     /// A contract `#[ensures(..)]` attribute injects a let binding for the check that runs at point of return.
     Contract,
 }
@@ -5013,7 +5012,7 @@ mod size_asserts {
     static_assert_size!(ImplItemKind<'_>, 40);
     static_assert_size!(Item<'_>, 88);
     static_assert_size!(ItemKind<'_>, 64);
-    static_assert_size!(LetStmt<'_>, 72);
+    static_assert_size!(LetStmt<'_>, 64);
     static_assert_size!(Param<'_>, 32);
     static_assert_size!(Pat<'_>, 80);
     static_assert_size!(PatKind<'_>, 56);

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -1112,8 +1112,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                                                 hir::Stmt {
                                                     kind:
                                                         hir::StmtKind::Let(hir::LetStmt {
-                                                            source:
-                                                                hir::LocalSource::AssignDesugar(_),
+                                                            source: hir::LocalSource::AssignDesugar,
                                                             ..
                                                         }),
                                                     ..

compiler/rustc_lint/src/let_underscore.rs

@@ -152,7 +152,7 @@ impl<'tcx> LateLintPass<'tcx> for LetUnderscore {
                 // We can't suggest `drop()` when we're on the top level.
                 drop_fn_start_end: can_use_init
                     .map(|init| (local.span.until(init.span), init.span.shrink_to_hi())),
-                is_assign_desugar: matches!(local.source, rustc_hir::LocalSource::AssignDesugar(_)),
+                is_assign_desugar: matches!(local.source, rustc_hir::LocalSource::AssignDesugar),
             };
             if is_sync_lock {
                 let span = MultiSpan::from_span(pat.span);

compiler/rustc_mir_build/src/builder/matches/mod.rs

@@ -2897,8 +2897,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
         for (_, node) in tcx.hir_parent_iter(var_id.0) {
             // FIXME(khuey) at what point is it safe to bail on the iterator?
             // Can we stop at the first non-Pat node?
-            if matches!(node, Node::LetStmt(&LetStmt { source: LocalSource::AssignDesugar(_), .. }))
-            {
+            if matches!(node, Node::LetStmt(&LetStmt { source: LocalSource::AssignDesugar, .. })) {
                 return false;
             }
         }