Don't stub out part of test

src/test/ui/issues/issue-47412.mir.stderr

@@ -7,7 +7,7 @@ LL |     match u.void {}
    = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior
 
 error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
-  --> $DIR/issue-47412.rs:21:11
+  --> $DIR/issue-47412.rs:20:11
    |
 LL |     match *ptr {}
    |           ^^^^ dereference of raw pointer

src/test/ui/issues/issue-47412.rs

@@ -12,8 +12,7 @@ fn union_field() {
     union Union { unit: (), void: Void }
     let u = Union { unit: () };
     match u.void {}
-    //[mir]~^ ERROR access to union field is unsafe
-    // FIXME(thir-unsafeck): AccessToUnionField unimplemented
+    //~^ ERROR access to union field is unsafe
 }
 
 fn raw_ptr_deref() {

src/test/ui/issues/issue-47412.thir.stderr

@@ -1,11 +1,19 @@
+error[E0133]: access to union field is unsafe and requires unsafe function or block
+  --> $DIR/issue-47412.rs:14:11
+   |
+LL |     match u.void {}
+   |           ^^^^^^ access to union field
+   |
+   = note: the field may not be properly initialized: using uninitialized data will cause undefined behavior
+
 error[E0133]: dereference of raw pointer is unsafe and requires unsafe function or block
-  --> $DIR/issue-47412.rs:21:11
+  --> $DIR/issue-47412.rs:20:11
    |
 LL |     match *ptr {}
    |           ^^^^ dereference of raw pointer
    |
    = note: raw pointers may be null, dangling or unaligned; they can violate aliasing rules and cause data races: all of these are undefined behavior
 
-error: aborting due to previous error
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0133`.