Fix a couple codegen crashers

lib/src/codegen/js_codegen.dart

 // Copyright (c) 2015, 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.
 
 library dev_compiler.src.codegen.js_codegen;
 
 import 'dart:collection' show HashSet, HashMap;
 import 'dart:io' show Directory, File;
 
 import 'package:analyzer/analyzer.dart' hide ConstantEvaluator;
@@ skipping 1742 matching lines @@
     if (expr is IndexExpression) {
       IndexExpression index = expr;
       return new IndexExpression.forTarget(
           _bindValue(scope, 'o', index.target, context: context),
           index.leftBracket,
           _bindValue(scope, 'i', index.index, context: context),
           index.rightBracket)..staticType = expr.staticType;
     } else if (expr is PropertyAccess) {
       PropertyAccess prop = expr;
       return new PropertyAccess(
-          _bindValue(scope, 'o', prop.target, context: context), prop.operator,
-          prop.propertyName)..staticType = expr.staticType;
+          _bindValue(scope, 'o', _getTarget(prop), context: context),
+          prop.operator, prop.propertyName)..staticType = expr.staticType;
     } else if (expr is PrefixedIdentifier) {
       PrefixedIdentifier ident = expr;
       return new PrefixedIdentifier(
           _bindValue(scope, 'o', ident.prefix, context: context), ident.period,
           ident.identifier)..staticType = expr.staticType;
     }
     return expr as SimpleIdentifier;
   }
 
   /// Creates a temporary to contain the value of [expr]. The temporary can be
@@ skipping 240 matching lines @@
         _visit(node.finallyBlock));
   }
 
   _visitCatch(NodeList<CatchClause> clauses) {
     if (clauses == null || clauses.isEmpty) return null;
 
     // TODO(jmesserly): need a better way to get a temporary variable.
     // This could incorrectly shadow a user's name.
     var savedCatch = _catchParameter;
 
-    if (clauses.length == 1) {
+    if (clauses.length == 1 && clauses.single.exceptionParameter != null) {
       // Special case for a single catch.
       _catchParameter = clauses.single.exceptionParameter;
     } else {
       _catchParameter = _createTemporary('e', rules.provider.dynamicType);
     }
 
-    JS.Statement catchBody = null;
+    JS.Statement catchBody = js.statement('throw #;', _visit(_catchParameter));
     for (var clause in clauses.reversed) {
       catchBody = _catchClauseGuard(clause, catchBody);
     }
 
     var catchVarDecl = _visit(_catchParameter);
     _catchParameter = savedCatch;
     return new JS.Catch(catchVarDecl, new JS.Block([catchBody]));
   }
 
   JS.Statement _catchClauseGuard(CatchClause clause, JS.Statement otherwise) {
@@ skipping 526 matching lines @@
     if (parent is MethodInvocation &&
         identical(parent.methodName, node)) return;
     if (parent is ConstructorName) return;
     if (parent is Label) return;
 
     if (node.inSetterContext() && node.staticElement == _variable) {
       _potentiallyMutated = true;
     }
   }
 }