Const-propagate casts

src/test/run-pass/cast-rfc0401.rs

@@ -166,7 +166,12 @@ fn main()
 
     assert!(foo as usize != bar as usize);
 
-    assert_eq!(foo as i16, foo as usize as i16);
+    // Taking a few bits of a function's address is totally pointless and we detect that
+    // Disabling the lint to ensure that the assertion can still be run
+    #[allow(const_err)]
+    {
+        assert_eq!(foo as i16, foo as usize as i16);
+    }
 
     // fptr-ptr-cast
 

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

@@ -24,5 +24,8 @@ fn main() {
     //~| WARN const_err
     println!("{}", 1/(false as u32));
     //~^ WARN const_err
+    //~| WARN const_err
     let _x = 1/(false as u32);
+    //~^ WARN const_err
+    //~| WARN const_err
 }

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

@@ -34,9 +34,27 @@ warning: this expression will panic at runtime
 LL |     let _x = 1/(1-1);
    |              ^^^^^^^ attempt to divide by zero
 
+warning: attempt to divide by zero
+  --> $DIR/promoted_errors.rs:25:20
+   |
+LL |     println!("{}", 1/(false as u32));
+   |                    ^^^^^^^^^^^^^^^^
+
 warning: this expression will panic at runtime
   --> $DIR/promoted_errors.rs:25:20
    |
 LL |     println!("{}", 1/(false as u32));
    |                    ^^^^^^^^^^^^^^^^ attempt to divide by zero
 
+warning: attempt to divide by zero
+  --> $DIR/promoted_errors.rs:28:14
+   |
+LL |     let _x = 1/(false as u32);
+   |              ^^^^^^^^^^^^^^^^
+
+warning: this expression will panic at runtime
+  --> $DIR/promoted_errors.rs:28:14
+   |
+LL |     let _x = 1/(false as u32);
+   |              ^^^^^^^^^^^^^^^^ attempt to divide by zero
+