cpsir: add support for deferred code

pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.dart

Index: pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.dart b/pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.dart
index ee7a8706b7f9d12dc3bc417cbaf4f3db11bc4c0a..9f2295a505e1d35c12ff6b89e245382cc755d504 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_ir_builder_task.dart
@@ -706,7 +706,21 @@ abstract class IrBuilderVisitor extends ast.Visitor<ir.Primitive>
   // ## Sends ##
   @override
   void previsitDeferredAccess(ast.Send node, PrefixElement prefix, _) {
-    giveup(node, 'deferred access is not implemented');
+    buildCheckDeferredIsLoaded(prefix, node,
+        sourceInformationBuilder.buildCall(node, node.selector));
+  }
+
+  ir.Primitive buildCheckDeferredIsLoaded(PrefixElement prefix, Spannable node,
+      SourceInformation sourceInformation) {
+    if (prefix == null) return null;
+    JavaScriptBackend backend = compiler.backend;
+    return irBuilder.buildStaticFunctionInvocation(
+        backend.helpers.checkDeferredIsLoaded,
+        CallStructure.TWO_ARGS, <ir.Primitive>[
+          irBuilder.buildStringConstant(
+              compiler.deferredLoadTask.getImportDeferName(node, prefix)),
+          irBuilder.buildStringConstant('${prefix.deferredImport.uri}'),
+        ], sourceInformation: sourceInformation);
   }
 
   ir.Primitive visitNamedArgument(ast.NamedArgument node) {
@@ -2581,6 +2595,11 @@ class GlobalProgramInformation {
 
   ClassElement get nullClass => _compiler.coreClasses.nullClass;
 
+  Element get loadLibraryFunction => _compiler.loadLibraryFunction;
+  String getImportDeferName(PrefixElement prefix) {
+    return _compiler.deferredLoadTask.getImportDeferName(null, prefix);
+  }
+
   DartType unaliasType(DartType type) => type.unaliased;
 
   TypeMask getTypeMaskForForeign(NativeBehavior behavior) {
@@ -3344,13 +3363,39 @@ class JsIrBuilderVisitor extends IrBuilderVisitor {
       ast.NodeList argumentsNode,
       CallStructure callStructure,
       _) {
+
+    ast.Send send = node.send;
+    // If an allocation refers to a type using a deferred import prefix (e.g.
+    // `new lib.A()`), we must ensure that the deferred import has already been
+    // loaded.
+    var prefix = compiler.deferredLoadTask.deferredPrefixElement(
+        send, elements);
+    if (prefix != null) {
+      buildCheckDeferredIsLoaded(prefix, send,
+          sourceInformationBuilder.buildCall(send, send.selector));
+    }
+
     List<ir.Primitive> arguments = argumentsNode.nodes.mapToList(visit);
     // Use default values from the effective target, not the immediate target.
     ConstructorElement target = constructor.effectiveTarget;
-    callStructure =
-        normalizeStaticArguments(callStructure, target, arguments);
+
+    // We also emit deferred import checks when using redirecting factories that
+    // refer to deferred prefixes.
+    if (constructor.isRedirectingFactory && !constructor.isCyclicRedirection) {
+      ConstructorElement current = constructor;
+      while (current.isRedirectingFactory) {
+        var prefix = current.redirectionDeferredPrefix;
+        if (prefix != null) {
+          buildCheckDeferredIsLoaded(prefix, send,
+              sourceInformationBuilder.buildCall(send, send.selector));
+        }
+        current = current.immediateRedirectionTarget;
+      }
+    }
+
+    callStructure = normalizeStaticArguments(callStructure, target, arguments);
     TypeMask allocationSiteType;
-    ast.Node send = node.send;
+
     if (Elements.isFixedListConstructorCall(constructor, send, compiler) ||
         Elements.isGrowableListConstructorCall(constructor, send, compiler) ||
         Elements.isFilledListConstructorCall(constructor, send, compiler) ||