Fix analyzer interpretation of 'ClassName?.staticMember'.

tests/language/if_null_assignment_behavior_test.dart

Index: tests/language/if_null_assignment_behavior_test.dart
diff --git a/tests/language/if_null_assignment_behavior_test.dart b/tests/language/if_null_assignment_behavior_test.dart
index bf01dbe43cbbe6a78e6da527cfe42e20edd5c4fc..765be9680dd54964e451a4794a6ac1e51256a89f 100644
--- a/tests/language/if_null_assignment_behavior_test.dart
+++ b/tests/language/if_null_assignment_behavior_test.dart
@@ -201,4 +201,14 @@ main() {
   check(1, () => x?.v ??= bad(), ['x', 'x.v']);     /// 27: continued
   xGetValue = new C('x'); yGetValue = 1;                 /// 28: ok
   check(1, () => x?.v ??= y, ['x', 'x.v', 'y', 'x.v=1']); /// 28: continued
+
+  // C?.v ??= e2 is equivalent to C.v ??= e2.
+  C.xGetValue = 1;                         /// 29: ok
+  check(1, () => C?.x ??= bad(), ['C.x']); /// 29: continued
+  h.C.xgetValue = 1;                           /// 30: ok
+  check(1, () => h.c?.x ??= bad(), ['h.C.x']); /// 30: continued
+  yGetValue = 1;                                     /// 31: ok
+  check(1, () => C?.x ??= y, ['C.x', 'y', 'C.x=1']); /// 31: continued
+  yGetValue = 1;                                           /// 32: ok
+  check(1, () => h.C?.x ??= y, ['h.C.x', 'y', 'h.C.x=1']); /// 32: continued
 }