Fix type inference of getters that "override" setters and vice versa.

pkg/kernel/test/class_hierarchy_test.dart

Index: pkg/kernel/test/class_hierarchy_test.dart
diff --git a/pkg/kernel/test/class_hierarchy_test.dart b/pkg/kernel/test/class_hierarchy_test.dart
index 3873b4824a012fb1e2530d04881cacdb626270bc..2c0fbd026b3d5f7cc2fd44542fb4fa273ed76a29 100644
--- a/pkg/kernel/test/class_hierarchy_test.dart
+++ b/pkg/kernel/test/class_hierarchy_test.dart
@@ -995,22 +995,27 @@ class B<T> extends self::A<self::B::T, core::bool> {}
   void _assertOverridePairs(Class class_, List<String> expected,
       {bool crossGettersSetters: false}) {
     List<String> overrideDescriptions = [];
-    hierarchy.forEachOverridePair(class_,
-        (Member declaredMember, Member interfaceMember, bool isSetter) {
+    void callback(
+        Member declaredMember, Member interfaceMember, bool isSetter) {
       String declaredSuffix;
       String interfaceSuffix;
+      declaredSuffix = isSetter ? '=' : '';
       if (crossGettersSetters) {
-        declaredSuffix = _isSetter(declaredMember) ? '=' : '';
-        interfaceSuffix = _isSetter(interfaceMember) ? '=' : '';
+        interfaceSuffix = isSetter ? '' : '=';
       } else {
-        declaredSuffix = isSetter ? '=' : '';
         interfaceSuffix = isSetter ? '=' : '';
       }
       String declaredName = '$declaredMember$declaredSuffix';
       String interfaceName = '$interfaceMember$interfaceSuffix';
       var desc = '$declaredName overrides $interfaceName';
       overrideDescriptions.add(desc);
-    }, crossGettersSetters: crossGettersSetters);
+    }
+
+    if (crossGettersSetters) {
+      hierarchy.forEachCrossOverridePair(class_, callback);
+    } else {
+      hierarchy.forEachOverridePair(class_, callback);
+    }
     expect(overrideDescriptions, unorderedEquals(expected));
   }
 
@@ -1043,8 +1048,4 @@ import "dart:core" as core;
 
     expect(actualText, expectedText);
   }
-
-  static bool _isSetter(Member member) {
-    return member is Procedure && member.kind == ProcedureKind.Setter;
-  }
 }