add C-unwind test case

Author: folkertdev

tests/ui/consts/const-extern-fn/const-extern-fn-requires-unsafe.rs

@@ -2,9 +2,17 @@ const unsafe extern "C" fn foo() -> usize {
     5
 }
 
+const unsafe extern "C-unwind" fn bar() -> usize {
+    5
+}
+
 fn main() {
     let a: [u8; foo()];
     //~^ call to unsafe function `foo` is unsafe and requires unsafe function or block
     foo();
     //~^ ERROR call to unsafe function `foo` is unsafe and requires unsafe function or block
+    let b: [u8; bar()];
+    //~^ call to unsafe function `bar` is unsafe and requires unsafe function or block
+    bar();
+    //~^ ERROR call to unsafe function `bar` is unsafe and requires unsafe function or block
 }

tests/ui/consts/const-extern-fn/const-extern-fn-requires-unsafe.stderr

@@ -1,19 +1,35 @@
 error[E0133]: call to unsafe function `foo` is unsafe and requires unsafe function or block
-  --> $DIR/const-extern-fn-requires-unsafe.rs:8:5
+  --> $DIR/const-extern-fn-requires-unsafe.rs:12:5
    |
 LL |     foo();
    |     ^^^^^ call to unsafe function
    |
    = note: consult the function's documentation for information on how to avoid undefined behavior
 
+error[E0133]: call to unsafe function `bar` is unsafe and requires unsafe function or block
+  --> $DIR/const-extern-fn-requires-unsafe.rs:16:5
+   |
+LL |     bar();
+   |     ^^^^^ call to unsafe function
+   |
+   = note: consult the function's documentation for information on how to avoid undefined behavior
+
 error[E0133]: call to unsafe function `foo` is unsafe and requires unsafe function or block
-  --> $DIR/const-extern-fn-requires-unsafe.rs:6:17
+  --> $DIR/const-extern-fn-requires-unsafe.rs:10:17
    |
 LL |     let a: [u8; foo()];
    |                 ^^^^^ call to unsafe function
    |
    = note: consult the function's documentation for information on how to avoid undefined behavior
 
-error: aborting due to 2 previous errors
+error[E0133]: call to unsafe function `bar` is unsafe and requires unsafe function or block
+  --> $DIR/const-extern-fn-requires-unsafe.rs:14:17
+   |
+LL |     let b: [u8; bar()];
+   |                 ^^^^^ call to unsafe function
+   |
+   = note: consult the function's documentation for information on how to avoid undefined behavior
+
+error: aborting due to 4 previous errors
 
 For more information about this error, try `rustc --explain E0133`.