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

src/test/ui/macros/macro-nested_expr.rs

@@ -0,0 +1,22 @@
+// run-pass
+// #42164
+
+#![feature(decl_macro)]
+#![allow(dead_code)]
+
+pub macro m($inner_str:expr) {
+    #[doc = $inner_str]
+    struct S;
+}
+
+macro_rules! define_f {
+    ($name:expr) => {
+        #[export_name = $name]
+        fn f() {}
+    }
+}
+
+fn main() {
+    define_f!(concat!("exported_", "f"));
+    m!(stringify!(foo));
+}