Auto merge of #34846 - jonas-schievink:issue34839, r=eddyb

Variant Size Differences: Erase regions before computing type layout

Fixes #34839

src/test/compile-fail/issue-34839.rs

@@ -0,0 +1,31 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(rustc_attrs)]
+#![allow(dead_code)]
+
+trait RegularExpression: Sized {
+    type Text;
+}
+
+struct ExecNoSyncStr<'a>(&'a u8);
+
+impl<'c> RegularExpression for ExecNoSyncStr<'c> {
+    type Text = u8;
+}
+
+struct FindCaptures<'t, R>(&'t R::Text) where R: RegularExpression, R::Text: 't;
+
+enum FindCapturesInner<'r, 't> {
+    Dynamic(FindCaptures<'t, ExecNoSyncStr<'r>>),
+}
+
+#[rustc_error]
+fn main() {}    //~ ERROR compilation successful