Avoid ICE by using delay_span_bug

Author: estebank

src/librustc_typeck/check/mod.rs

@@ -5653,10 +5653,11 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
             match self.at(&self.misc(span), self.param_env).sup(impl_ty, self_ty) {
                 Ok(ok) => self.register_infer_ok_obligations(ok),
                 Err(_) => {
-                    span_bug!(span,
+                    self.tcx.sess.delay_span_bug(span, &format!(
                         "instantiate_value_path: (UFCS) {:?} was a subtype of {:?} but now is not?",
                         self_ty,
-                        impl_ty);
+                        impl_ty,
+                    ));
                 }
             }
         }

src/test/ui/issues/issue-53498.rs

@@ -0,0 +1,17 @@
+pub mod test {
+    pub struct A;
+    pub struct B;
+    pub struct Foo<T>(T);
+
+    impl Foo<A> {
+        fn foo() {}
+    }
+
+    impl Foo<B> {
+        fn foo() {}
+    }
+}
+
+fn main() {
+    test::Foo::<test::B>::foo(); //~ ERROR method `foo` is private
+}

src/test/ui/issues/issue-53498.stderr

@@ -0,0 +1,9 @@
+error[E0624]: method `foo` is private
+  --> $DIR/issue-53498.rs:16:5
+   |
+LL |     test::Foo::<test::B>::foo();
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0624`.