Enable top level inference of instance property gets/sets.

pkg/front_end/lib/src/fasta/kernel/kernel_shadow_ast.dart

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// This file declares a "shadow hierarchy" of concrete classes which extend
 /// the kernel class hierarchy, adding methods and fields needed by the
 /// BodyBuilder.
 ///
 /// Instances of these classes may be created using the factory methods in
 /// `ast_factory.dart`.
@@ skipping 1391 matching lines @@
     if (read != null) {
       inferrer.findPropertyGetMember(receiverType, read, silent: true);
     }
     Member writeMember;
     if (write != null) {
       writeMember = inferrer.findPropertySetMember(receiverType, write);
       if (inferrer.isTopLevel &&
           ((writeMember is Procedure &&
                   writeMember.kind == ProcedureKind.Setter) ||
               writeMember is Field)) {
-        // References to fields and setters can't be relied upon for top level
-        // inference.
-        inferrer.recordNotImmediatelyEvident(fileOffset);
+        if (TypeInferenceEngineImpl.fullTopLevelInference) {
+          if (writeMember is KernelField && writeMember._fieldNode != null) {
+            inferrer.engine
+                .inferFieldFused(writeMember._fieldNode, inferrer.fieldNode);
+          }
+        } else {
+          // References to fields and setters can't be relied upon for top level
+          // inference.
+          inferrer.recordNotImmediatelyEvident(fileOffset);
+        }
       }
     }
     // To replicate analyzer behavior, we base type inference on the write
     // member.  TODO(paulberry): would it be better to use the read member when
     // doing compound assignment?
     var writeContext = writeMember?.setterType;
     var inferredType = _inferRhs(inferrer, writeContext);
     inferrer.listener.propertyAssignExit(desugared, inferredType);
     return inferredType;
   }
@@ skipping 33 matching lines @@
     typeNeeded =
         inferrer.listener.propertyGetEnter(this, typeContext) || typeNeeded;
     // First infer the receiver so we can look up the getter that was invoked.
     var receiverType = inferrer.inferExpression(receiver, null, true);
     Member interfaceMember =
         inferrer.findInterfaceMember(receiverType, name, fileOffset);
     if (inferrer.isTopLevel &&
         ((interfaceMember is Procedure &&
                 interfaceMember.kind == ProcedureKind.Getter) ||
             interfaceMember is Field)) {
-      // References to fields and getters can't be relied upon for top level
-      // inference.
-      inferrer.recordNotImmediatelyEvident(fileOffset);
+      if (TypeInferenceEngineImpl.fullTopLevelInference) {
+        if (interfaceMember is KernelField &&
+            interfaceMember._fieldNode != null) {
+          inferrer.engine
+              .inferFieldFused(interfaceMember._fieldNode, inferrer.fieldNode);
+        }
+      } else {
+        // References to fields and getters can't be relied upon for top level
+        // inference.
+        inferrer.recordNotImmediatelyEvident(fileOffset);
+      }
     }
     interfaceTarget = interfaceMember;
     var inferredType =
         inferrer.getCalleeType(interfaceMember, receiverType, name);
     // TODO(paulberry): Infer tear-off type arguments if appropriate.
     inferrer.listener.propertyGetExit(this, inferredType);
     return typeNeeded ? inferredType : null;
   }
 }
 
@@ skipping 792 matching lines @@
   }
 
   transformChildren(v) {
     return internalError("Internal error: Unsupported operation.");
   }
 
   visitChildren(v) {
     return internalError("Internal error: Unsupported operation.");
   }
 }