add test to verify that rust-lang#132391 can be closed

Author: jdonszelmann

Diff for: tests/ui/attributes/malformed-fn-align.rs

@@ -0,0 +1,7 @@
+#![feature(fn_align)]
+#![crate_type = "lib"]
+
+trait MyTrait {
+    #[repr(align)] //~ ERROR invalid `repr(align)` attribute: `align` needs an argument
+    fn myfun();
+}

Diff for: tests/ui/attributes/malformed-fn-align.stderr

@@ -0,0 +1,9 @@
+error[E0589]: invalid `repr(align)` attribute: `align` needs an argument
+  --> $DIR/malformed-fn-align.rs:5:12
+   |
+LL |     #[repr(align)]
+   |            ^^^^^ help: supply an argument here: `align(...)`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0589`.