Make try/catch/finally work with Kernel code and some refactoring.

pkg/compiler/lib/src/ssa/kernel_ast_adapter.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 file.
 
 import 'package:js_runtime/shared/embedded_names.dart';
 import 'package:kernel/ast.dart' as ir;
 
 import '../constants/expressions.dart';
 import '../common.dart';
 import '../common/names.dart';
@@ skipping 336 matching lines @@
 
   ir.Procedure get mapLiteralConstructor =>
       kernel.functions[_backend.helpers.mapLiteralConstructor];
 
   ir.Procedure get mapLiteralConstructorEmpty =>
       kernel.functions[_backend.helpers.mapLiteralConstructorEmpty];
 
   ir.Procedure get mapLiteralUntypedEmptyMaker =>
       kernel.functions[_backend.helpers.mapLiteralUntypedEmptyMaker];
 
+  ir.Procedure get exceptionUnwrapper =>
+      kernel.functions[_backend.helpers.exceptionUnwrapper];
+
+  TypeMask get exceptionUnwrapperType =>
+      TypeMaskFactory.inferredReturnTypeForElement(
+          _backend.helpers.exceptionUnwrapper, _globalInferenceResults);
+
+  ir.Procedure get traceFromException =>
+      kernel.functions[_backend.helpers.traceFromException];
+
+  TypeMask get traceFromExceptionType =>
+      TypeMaskFactory.inferredReturnTypeForElement(
+          _backend.helpers.traceFromException, _globalInferenceResults);
+
   ir.Procedure get mapLiteralUntypedMaker =>
       kernel.functions[_backend.helpers.mapLiteralUntypedMaker];
 
   MemberElement get jsIndexableLength => _backend.helpers.jsIndexableLength;
 
   ir.Procedure get checkConcurrentModificationError =>
       kernel.functions[_backend.helpers.checkConcurrentModificationError];
 
   TypeMask get checkConcurrentModificationErrorReturnType =>
       TypeMaskFactory.inferredReturnTypeForElement(
@@ skipping 487 matching lines @@
     astAdapter.reporter.internalError(
         CURRENT_ELEMENT_SPANNABLE, "Unexpected constant target: $element.");
     return null;
   }
 
   @override
   ConstantExpression visitStringLiteral(ir.StringLiteral node) {
     return new StringConstantExpression(node.value);
   }
 }