kernel -> ssa: implement literal maps

pkg/compiler/lib/src/kernel/kernel_visitor.dart

 // Copyright (c) 2016, 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.md file.
 
 import 'package:kernel/ast.dart' as ir;
 import 'package:kernel/frontend/accessors.dart'
     show
         Accessor,
         IndexAccessor,
         NullAwarePropertyAccessor,
@@ skipping 861 matching lines @@
   @override
   ir.MapLiteral visitLiteralMap(LiteralMap node) {
     // TODO(ahe): Type arguments.
     List<ir.MapEntry> entries = <ir.MapEntry>[];
     for (LiteralMapEntry entry in node.entries.nodes) {
       entries.add(new ir.MapEntry(
           visitForValue(entry.key), visitForValue(entry.value)));
     }
     List<ir.DartType> typeArguments =
         computeTypesFromTypes(node.typeArguments, expected: 2);
-    return new ir.MapLiteral(entries,
-        keyType: typeArguments.first,
-        valueType: typeArguments.last,
-        // TODO(ahe): Should Constness be validated?
-        isConst: node.isConst);
+    return associateNode(
+        new ir.MapLiteral(entries,
+            keyType: typeArguments.first,
+            valueType: typeArguments.last,
+            // TODO(ahe): Should Constness be validated?
+            isConst: node.isConst),
+        node);
   }
 
   @override
   visitLiteralMapEntry(LiteralMapEntry node) {
     // Shouldn't be called. Handled by [visitLiteralMap].
     return internalError(node, "LiteralMapEntry");
   }
 
   @override
   ir.NullLiteral visitLiteralNull(LiteralNull node) {
@@ skipping 1853 matching lines @@
       : this(null, true, node, initializers);
 
   accept(ir.Visitor v) => throw "unsupported";
 
   visitChildren(ir.Visitor v) => throw "unsupported";
 
   String toString() {
     return "IrFunction($kind, $isConstructor, $node, $initializers)";
   }
 }