add test for invalid places of repr align

Author: fee1-dead

tests/ui/attributes/invalid-repr.rs

@@ -0,0 +1,5 @@
+#[repr(align(16))]
+//~^ ERROR attribute should be applied to a struct, enum, function, associated function, or union
+pub type Foo = i32;
+
+fn main() {}

tests/ui/attributes/invalid-repr.stderr

@@ -0,0 +1,12 @@
+error[E0517]: attribute should be applied to a struct, enum, function, associated function, or union
+  --> $DIR/invalid-repr.rs:1:8
+   |
+LL | #[repr(align(16))]
+   |        ^^^^^^^^^
+LL |
+LL | pub type Foo = i32;
+   | ------------------- not a struct, enum, function, associated function, or union
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0517`.