permit negative impls for non-auto traits

src/test/ui/error-codes/E0192.rs

@@ -1,12 +0,0 @@
-#![feature(optin_builtin_traits)]
-
-trait Trait {
-    type Bar;
-}
-
-struct Foo;
-
-impl !Trait for Foo { } //~ ERROR E0192
-
-fn main() {
-}

src/test/ui/error-codes/E0192.stderr

@@ -1,11 +0,0 @@
-error[E0192]: invalid negative impl
-  --> $DIR/E0192.rs:9:6
-   |
-LL | impl !Trait for Foo { }
-   |      ^^^^^^
-   |
-   = note: negative impls are only allowed for auto traits, like `Send` and `Sync`
-
-error: aborting due to previous error
-
-For more information about this error, try `rustc --explain E0192`.