Rollup merge of rust-lang#86381 - yerke:add-test-for-issue-39161, r=JohnTitor

Add regression test for issue rust-lang#39161

Closes rust-lang#39161

Based on feedback from ``@JohnTitor`` in rust-lang#71333

r? ``@JohnTitor``

Author: JohnTitor

src/test/ui/consts/issue-39161-bogus-error.rs

@@ -0,0 +1,13 @@
+// check-pass
+
+pub struct X {
+    pub a: i32,
+    pub b: i32,
+}
+
+fn main() {
+    const DX: X = X { a: 0, b: 0 };
+    const _X1: X = X { a: 1, ..DX };
+    let _x2 = X { a: 1, b: 2, ..DX };
+    const _X3: X = X { a: 1, b: 2, ..DX };
+}