Fix ICE with feature self_struct_ctor

src/test/ui/issues/issue-56202.rs

@@ -0,0 +1,15 @@
+#![feature(self_struct_ctor)]
+
+trait FooTrait {}
+
+trait BarTrait {
+    fn foo<T: FooTrait>(_: T) -> Self;
+}
+
+struct FooStruct(u32);
+
+impl BarTrait for FooStruct {
+    fn foo<T: FooTrait>(_: T) -> Self {
+        Self(u32::default())
+    }
+}

src/test/ui/issues/issue-56202.stderr

@@ -0,0 +1,7 @@
+error[E0601]: `main` function not found in crate `issue_56202`
+   |
+   = note: consider adding a `main` function to `$DIR/issue-56202.rs`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0601`.