Do not analyze assert when assertions are disabled.

sdk/lib/_internal/compiler/implementation/dart_backend/placeholder_collector.dart

 // Copyright (c) 2012, 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.
 
 part of dart_backend;
 
 class LocalPlaceholder {
   final String identifier;
   final Set<Node> nodes;
   LocalPlaceholder(this.identifier) : nodes = new Set<Node>();
@@ skipping 26 matching lines @@
 
 class DeclarationTypePlaceholder {
   final TypeAnnotation typeNode;
   final bool requiresVar;
   DeclarationTypePlaceholder(this.typeNode, this.requiresVar);
 }
 
 class SendVisitor extends ResolvedVisitor {
   final PlaceholderCollector collector;
 
-  get compiler => collector.compiler;
-
-  SendVisitor(this.collector, TreeElements elements) : super(elements);
+  SendVisitor(collector, TreeElements elements)
+      : this.collector = collector,
+        super(elements, collector.compiler);
 
   visitOperatorSend(Send node) {
   }
 
   visitForeignSend(Send node) {}
 
   visitSuperSend(Send node) {
     Element element = elements[node];
     if (element != null && element.isConstructor()) {
       collector.makeRedirectingConstructorPlaceholder(node.selector, element);
@@ skipping 37 matching lines @@
         // in case of A(int this.f());
         if (node.selector is Identifier) {
           collector.tryMakeLocalPlaceholder(element, node.selector);
         } else {
           assert(node.selector is FunctionExpression);
         }
       }
     }
   }
 
+  visitAssert(node) {
+    visitStaticSend(node);
+  }
+
   visitStaticSend(Send node) {
     final element = elements[node];
     collector.backend.registerStaticSend(element, node);
 
     if (Elements.isUnresolved(element)
         || identical(element, compiler.assertMethod)) {
       return;
     }
     if (element.isConstructor() || element.isFactoryConstructor()) {
       // Rename named constructor in redirection position:
@@ skipping 505 matching lines @@
 
   visitBlock(Block node) {
     for (Node statement in node.statements.nodes) {
       if (statement is VariableDefinitions) {
         makeVarDeclarationTypePlaceholder(statement);
       }
     }
     node.visitChildren(this);
   }
 }