Add type inference for invalid constructor initializers.

R=scheglov@google.com

Review-Url: https://codereview.chromium.org/2998573002 .

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

@@ -3137,7 +3137,8 @@ class BodyBuilder extends ScopeListener<JumpTarget> implements BuilderHelper {
   Initializer buildInvalidInitializer(Expression expression,
       [int charOffset = -1]) {
     needsImplicitSuperInitializer = false;
-    return new LocalInitializer(new VariableDeclaration.forValue(expression))
+    return new KernelInvalidInitializer(
+        new VariableDeclaration.forValue(expression))
       ..fileOffset = charOffset;
   }
 

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

@@ -1019,6 +1019,19 @@ class KernelIntLiteral extends IntLiteral implements KernelExpression {
   }
 }
 
+/// Concrete shadow object representing an invalid initializer in kernel form.
+class KernelInvalidInitializer extends LocalInitializer
+    implements KernelInitializer {
+  KernelInvalidInitializer(VariableDeclaration variable) : super(variable);
+
+  @override
+  void _inferInitializer(KernelTypeInferrer inferrer) {
+    inferrer.listener.invalidInitializerEnter(this);
+    inferrer.inferExpression(variable.initializer, null, false);
+    inferrer.listener.invalidInitializerExit(this);
+  }
+}
+
 /// Concrete shadow object representing a non-inverted "is" test in kernel form.
 class KernelIsExpression extends IsExpression implements KernelExpression {
   KernelIsExpression(Expression operand, DartType type) : super(operand, type);

pkg/front_end/lib/src/fasta/type_inference/type_inference_listener.dart

@@ -232,6 +232,12 @@ class TypeInferenceListener
   void intLiteralExit(IntLiteral expression, DartType inferredType) =>
       genericExpressionExit("intLiteral", expression, inferredType);
 
+  void invalidInitializerEnter(LocalInitializer initializer) =>
+      genericInitializerEnter("invalidInitializer", initializer);
+
+  void invalidInitializerExit(LocalInitializer initializer) =>
+      genericInitializerExit("invalidInitializer", initializer);
+
   bool isExpressionEnter(IsExpression expression, DartType typeContext) =>
       genericExpressionEnter("isExpression", expression, typeContext);