Drive-by-cleanup: Don't emit thir::ExprKind::NeverToAny for ! -> !

Author: WaffleLapkin

tests/fail/never_say_never.rs

@@ -6,10 +6,8 @@
 
 fn main() {
     let y = &5;
-    let x: ! = unsafe {
-        *(y as *const _ as *const !) //~ ERROR: entering unreachable code
-    };
-    f(x)
+    let x: ! = unsafe { *(y as *const _ as *const !) };
+    f(x) //~ ERROR: entering unreachable code
 }
 
 fn f(x: !) -> ! {

tests/fail/never_say_never.stderr

@@ -1,8 +1,8 @@
 error: Undefined Behavior: entering unreachable code
   --> $DIR/never_say_never.rs:LL:CC
    |
-LL |         *(y as *const _ as *const !)
-   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ entering unreachable code
+LL |     f(x)
+   |     ^^^^ entering unreachable code
    |
    = help: this indicates a bug in the program: it performed an invalid operation, and caused Undefined Behavior
    = help: see https://doc.rust-lang.org/nightly/reference/behavior-considered-undefined.html for further information