dart2js-kernel: implement rethrow

pkg/compiler/lib/src/ssa/builder_kernel.dart

Index: pkg/compiler/lib/src/ssa/builder_kernel.dart
diff --git a/pkg/compiler/lib/src/ssa/builder_kernel.dart b/pkg/compiler/lib/src/ssa/builder_kernel.dart
index 013ef4be68741a32f025b15a4e042afc1ef59ed0..08958fdf7d5c33a47087d6281c89c8958aa42d87 100644
--- a/pkg/compiler/lib/src/ssa/builder_kernel.dart
+++ b/pkg/compiler/lib/src/ssa/builder_kernel.dart
@@ -15,12 +15,14 @@ import '../constants/values.dart'
         ConstantValue,
         InterceptorConstantValue,
         StringConstantValue,
+        SyntheticConstantValue,
+  //SyntheticConstantKind,

[sra1, 2017/01/09 19:20:17]

I'm fixing this now and reformatting

         TypeConstantValue;
 import '../elements/resolution_types.dart';
 import '../elements/elements.dart';
 import '../io/source_information.dart';
 import '../js/js.dart' as js;
-import '../js_backend/backend.dart' show JavaScriptBackend;
+import '../js_backend/backend.dart' show JavaScriptBackend, SyntheticConstantKind;
 import '../kernel/kernel.dart';
 import '../native/native.dart' as native;
 import '../resolution/tree_elements.dart';
@@ -2214,6 +2216,20 @@ class KernelSsaBuilder extends ir.Visitor with GraphBuilder {
   }
 
   @override
+  void visitRethrow(ir.Rethrow rethrowNode) {
+    HInstruction exception = rethrowableException;
+    if (exception == null) {
+      exception = graph.addConstantNull(closedWorld);
+      reporter.internalError(node, 'rethrowableException should not be null.');
+    }
+    Sourceinformation sourceInformation = null;
+    closeAndGotoExit(new HThrow(exception, sourceInformation, isRethrow: true));
+    // ir.Rethrow is an expression so we need to push a value - a constant with
+    // no type.
+    stack.add(graph.addConstantUnreachable(closedWorld));
+  }
+
+  @override
   void visitThisExpression(ir.ThisExpression thisExpression) {
     stack.add(localsHandler.readThis());
   }