Revive throw as an expression but not for rethrow.

sdk/lib/_internal/compiler/implementation/ssa/builder.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 ssa;
 
 /**
  * A special element for the extra parameter taken by intercepted
  * methods. We need to override [Element.computeType] because our
  * optimizers may look at its declared type.
@@ skipping 3746 matching lines @@
     handleInTryStatement();
 
     if (!inliningStack.isEmpty) {
       localsHandler.updateLocal(returnElement, value);
     } else {
       close(attachPosition(new HReturn(value), node)).addSuccessor(graph.exit);
     }
   }
 
   visitThrow(Throw node) {
+    HBasicBlock block;
     if (node.expression == null) {
       HInstruction exception = rethrowableException;
       if (exception == null) {
         exception = graph.addConstantNull(constantSystem);
         compiler.internalError(
             'rethrowableException should not be null', node: node);
       }
-      close(new HThrow(exception, isRethrow: true));
+      block = close(new HThrow(exception, isRethrow: true));
     } else {
       visit(node.expression);
-      close(new HThrow(pop()));
+      block = close(new HThrow(pop()));
     }
+    HBasicBlock newBlock = addNewBlock();
+    block.addSuccessor(newBlock);
+    open(newBlock);
+    stack.add(graph.addConstantNull(constantSystem));
   }
 
   visitTypeAnnotation(TypeAnnotation node) {
     compiler.internalError('visiting type annotation in SSA builder',
                            node: node);
   }
 
   visitVariableDefinitions(VariableDefinitions node) {
     for (Link<Node> link = node.definitions.nodes;
          !link.isEmpty;
@@ skipping 1202 matching lines @@
           new HSubGraphBlockInformation(elseBranch.graph));
 
     HBasicBlock conditionStartBlock = conditionBranch.block;
     conditionStartBlock.setBlockFlow(info, joinBlock);
     SubGraph conditionGraph = conditionBranch.graph;
     HIf branch = conditionGraph.end.last;
     assert(branch is HIf);
     branch.blockInformation = conditionStartBlock.blockFlow;
   }
 }