tests: Move run-pass tests without naming conflicts to ui

src/test/ui/for-loop-while/liveness-assign-imm-local-after-loop.rs

@@ -0,0 +1,18 @@
+// run-pass
+#![allow(dead_code)]
+#![allow(unused_assignments)]
+// pretty-expanded FIXME #23616
+
+#![allow(unreachable_code)]
+#![allow(unused_variables)]
+
+fn test(_cond: bool) {
+    let v: isize;
+    v = 1;
+    loop { } // loop never terminates, so no error is reported
+    v = 2;
+}
+
+pub fn main() {
+    // note: don't call test()... :)
+}