Add test for issue #83474

Author: KSBilodeau

src/test/ui/lang-items/lang-item-generic-requirements.rs

@@ -1,5 +1,5 @@
-// Checks that declaring a lang item with the wrong number
-// of generic arguments errors rather than crashing (issue #83893, #87573, part of #9307, #79559).
+// Checks that declaring a lang item with the wrong number of generic arguments errors rather than
+// crashing (issue #83474, #83893, #87573, part of #9307, #79559).
 
 #![feature(lang_items, no_core)]
 #![no_core]
@@ -25,6 +25,10 @@ struct MyPhantomData<T, U>;
 //~^ ERROR parameter `T` is never used
 //~| ERROR parameter `U` is never used
 
+#[lang = "owned_box"]
+//~^ ERROR `owned_box` language item must be applied to a struct with at least 1 generic argument
+struct Foo;
+
 // When the `start` lang item is missing generics very odd things can happen, especially when
 // it comes to cross-crate monomorphization
 #[lang = "start"]
@@ -48,6 +52,9 @@ fn ice() {
 
     // Use phantomdata
     let _ = MyPhantomData::<(), i32>;
+
+    // Use Foo
+    let _: () = Foo;
 }
 
 // use `start`

src/test/ui/lang-items/lang-item-generic-requirements.stderr

@@ -32,8 +32,17 @@ LL |
 LL | struct MyPhantomData<T, U>;
    |                     ------ this struct has 2 generic arguments
 
+error[E0718]: `owned_box` language item must be applied to a struct with at least 1 generic argument
+  --> $DIR/lang-item-generic-requirements.rs:28:1
+   |
+LL | #[lang = "owned_box"]
+   | ^^^^^^^^^^^^^^^^^^^^^
+LL |
+LL | struct Foo;
+   |           - this struct has 0 generic arguments
+
 error[E0718]: `start` language item must be applied to a function with 1 generic argument
-  --> $DIR/lang-item-generic-requirements.rs:30:1
+  --> $DIR/lang-item-generic-requirements.rs:34:1
    |
 LL | #[lang = "start"]
    | ^^^^^^^^^^^^^^^^^
@@ -59,7 +68,7 @@ LL | struct MyPhantomData<T, U>;
    = help: consider removing `U` or referring to it in a field
    = help: if you intended `U` to be a const parameter, use `const U: usize` instead
 
-error: aborting due to 7 previous errors
+error: aborting due to 8 previous errors
 
 Some errors have detailed explanations: E0392, E0718.
 For more information about an error, try `rustc --explain E0392`.