Add type inference for while and do loops.

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 534 matching lines @@
   }
 
   @override
   DartType _inferExpression(
       KernelTypeInferrer inferrer, DartType typeContext, bool typeNeeded) {
     // TODO(scheglov): implement.
     return typeNeeded ? const DynamicType() : null;
   }
 }
 
+/// Concrete shadow object representing a do loop in kernel form.
+class KernelDoStatement extends DoStatement implements KernelStatement {
+  KernelDoStatement(Statement body, Expression condition)
+      : super(body, condition);
+
+  @override
+  void _inferStatement(KernelTypeInferrer inferrer) {
+    inferrer.listener.doStatementEnter(this);
+    inferrer.inferStatement(body);
+    inferrer.inferExpression(
+        condition, inferrer.coreTypes.boolClass.rawType, false);
+    inferrer.listener.doStatementExit(this);
+  }
+}
+
 /// Concrete shadow object representing a double literal in kernel form.
 class KernelDoubleLiteral extends DoubleLiteral implements KernelExpression {
   KernelDoubleLiteral(double value) : super(value);
 
   @override
   void _collectDependencies(KernelDependencyCollector collector) {
     // No inference dependencies.
   }
 
   @override
@@ skipping 1603 matching lines @@
           'promotedType', new InstrumentationValueForType(promotedType));
     }
     this.promotedType = promotedType;
     var inferredType =
         typeNeeded ? (promotedType ?? declaredOrInferredType) : null;
     inferrer.listener.variableGetExit(this, inferredType);
     return inferredType;
   }
 }
 
+/// Concrete shadow object representing a while loop in kernel form.
+class KernelWhileStatement extends WhileStatement implements KernelStatement {
+  KernelWhileStatement(Expression condition, Statement body)
+      : super(condition, body);
+
+  @override
+  void _inferStatement(KernelTypeInferrer inferrer) {
+    inferrer.listener.whileStatementEnter(this);
+    inferrer.inferExpression(
+        condition, inferrer.coreTypes.boolClass.rawType, false);
+    inferrer.inferStatement(body);
+    inferrer.listener.whileStatementExit(this);
+  }
+}
+
 /// Concrete shadow object representing a yield statement in kernel form.
 class KernelYieldStatement extends YieldStatement implements KernelStatement {
   KernelYieldStatement(Expression expression, {bool isYieldStar: false})
       : super(expression, isYieldStar: isYieldStar);
 
   @override
   void _inferStatement(KernelTypeInferrer inferrer) {
     inferrer.listener.yieldStatementEnter(this);
     var closureContext = inferrer.closureContext;
     var typeContext =
@@ skipping 25 matching lines @@
   }
 
   transformChildren(v) {
     return internalError("Internal error: Unsupported operation.");
   }
 
   visitChildren(v) {
     return internalError("Internal error: Unsupported operation.");
   }
 }