Consistent with treating Ctor Call as Struct in liveness analysis

Signed-off-by: xizheyin <[email protected]>

Author: xizheyin

compiler/rustc_passes/src/liveness.rs

@@ -1021,7 +1021,10 @@ impl<'a, 'tcx> Liveness<'a, 'tcx> {
             }
 
             hir::ExprKind::Call(ref f, args) => {
-                let succ = self.check_is_ty_uninhabited(expr, succ);
+                let is_ctor = |f: &Expr<'_>| matches!(f.kind, hir::ExprKind::Path(hir::QPath::Resolved(_, path)) if matches!(path.res, rustc_hir::def::Res::Def(rustc_hir::def::DefKind::Ctor(_, _), _)));
+                let succ =
+                    if !is_ctor(f) { self.check_is_ty_uninhabited(expr, succ) } else { succ };
+
                 let succ = self.propagate_through_exprs(args, succ);
                 self.propagate_through_expr(f, succ)
             }

tests/ui/reachable/unreachable-by-call-arguments-issue-139627.rs

@@ -1,13 +1,14 @@
+//@ check-pass
 #![deny(unreachable_code)]
 #![deny(unused)]
 
 pub enum Void {}
 
 pub struct S<T>(T);
 
-pub fn foo(void: Void, void1: Void) { //~ ERROR unused variable: `void1`
-    let s = S(void); //~ ERROR unused variable: `s`
-    drop(s); //~ ERROR unreachable expression
+pub fn foo(void: Void, void1: Void) {
+    let s = S(void);
+    drop(s);
     let s1 = S { 0: void1 };
     drop(s1);
 }