Fix first part on liveness analysis of bug https://code.google.com/p/dart/issues/detail?id=9687: a …

sdk/lib/_internal/compiler/implementation/ssa/codegen.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;
 
 class SsaCodeGeneratorTask extends CompilerTask {
 
   final JavaScriptBackend backend;
 
@@ skipping 319 matching lines @@
     allocator.visitGraph(graph);
     variableNames = allocator.names;
     shouldGroupVarDeclarations = allocator.names.numberOfVariables > 1;
 
     // Don't register a return type for lazily initialized variables.
     if (work.element is! FunctionElement) return;
 
     // Register return types to the backend.
     graph.exit.predecessors.forEach((HBasicBlock block) {
       HInstruction last = block.last;
-      assert(last is HGoto || last is HReturn);
+      assert(last is HGoto || last is HReturn || last is HThrow);
       if (last is HReturn) {
         backend.registerReturnType(
             work.element, last.inputs[0].instructionType);
-      } else {
+      } else if (last is HGoto) {
         backend.registerReturnType(work.element, HType.NULL);
       }
     });
   }
 
   void handleDelayedVariableDeclarations() {
     // If we have only one variable declaration and the first statement is an
     // assignment to that variable then we can merge the two.  We count the
     // number of variables in the variable allocator to try to avoid this issue,
     // but it sometimes happens that the variable allocator introduces a
@@ skipping 2632 matching lines @@
   if (leftType.canBeNull() && rightType.canBeNull()) {
     if (left.isConstantNull() || right.isConstantNull() ||
         (leftType.isPrimitive() && leftType == rightType)) {
       return '==';
     }
     return null;
   } else {
     return '===';
   }
 }