Detect overflows of non u32 shifts

src/test/ui/const-eval/shift_overflow.rs

@@ -0,0 +1,19 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+enum Foo {
+    // test that we detect overflows for non-u32 discriminants
+    X = 1 << ((u32::max_value() as u64) + 1), //~ ERROR E0080
+    Y = 42,
+}
+
+
+fn main() {
+}

src/test/ui/const-eval/shift_overflow.stderr

@@ -0,0 +1,9 @@
+error[E0080]: could not evaluate enum discriminant
+  --> $DIR/shift_overflow.rs:13:9
+   |
+LL |     X = 1 << ((u32::max_value() as u64) + 1), //~ ERROR E0080
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ attempt to shift left with overflow
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0080`.