FIXUP of C# 8 tests - controlflow for null coalesching assignment.

Author: michaelnebel

csharp/ql/test/library-tests/csharp8/NullCoalescingControlFlow.expected

@@ -4,7 +4,8 @@
 | NullCoalescingAssignment.cs:7:9:7:24 | ... ...; | NullCoalescingAssignment.cs:7:20:7:23 | null | semmle.label | successor |
 | NullCoalescingAssignment.cs:7:16:7:23 | Object o = ... | NullCoalescingAssignment.cs:8:9:8:19 | ...; | semmle.label | successor |
 | NullCoalescingAssignment.cs:7:20:7:23 | null | NullCoalescingAssignment.cs:7:16:7:23 | Object o = ... | semmle.label | successor |
-| NullCoalescingAssignment.cs:8:9:8:9 | access to local variable o | NullCoalescingAssignment.cs:8:15:8:18 | this access | semmle.label | successor |
+| NullCoalescingAssignment.cs:8:9:8:9 | access to local variable o | NullCoalescingAssignment.cs:8:9:8:18 | ... ??= ... | semmle.label | non-null |
+| NullCoalescingAssignment.cs:8:9:8:9 | access to local variable o | NullCoalescingAssignment.cs:8:15:8:18 | this access | semmle.label | null |
 | NullCoalescingAssignment.cs:8:9:8:18 | ... ??= ... | NullCoalescingAssignment.cs:5:10:5:23 | exit NullCoalescing (normal) | semmle.label | successor |
 | NullCoalescingAssignment.cs:8:9:8:19 | ...; | NullCoalescingAssignment.cs:8:9:8:9 | access to local variable o | semmle.label | successor |
 | NullCoalescingAssignment.cs:8:15:8:18 | this access | NullCoalescingAssignment.cs:8:9:8:18 | ... ??= ... | semmle.label | successor |