Lazily generate local var descriptors.

runtime/vm/object_test.cc

 // 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.
 
 #include "platform/globals.h"
 
 #include "vm/assembler.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart_api_impl.h"
 #include "vm/dart_entry.h"
@@ skipping 2905 matching lines @@
   EXPECT_EQ(RawPcDescriptors::kOther, iter.Kind());
 
   EXPECT_EQ(false, iter.MoveNext());
 }
 
 
 TEST_CASE(PcDescriptorsCompressed) {
   const int kNumEntries = 6;
   // Add PcDescriptors to the code.
   PcDescriptors& descriptors = PcDescriptors::Handle();
-  // PcDescritpors have no try-index.
+  // PcDescriptors have no try-index.
   descriptors ^= PcDescriptors::New(kNumEntries, false);
   descriptors.AddDescriptor(0, 10, RawPcDescriptors::kOther, 1, 20, -1);
   descriptors.AddDescriptor(1, 20, RawPcDescriptors::kDeopt, 2, 30, -1);
   descriptors.AddDescriptor(2, 30, RawPcDescriptors::kOther, 3, 40, -1);
   descriptors.AddDescriptor(3, 10, RawPcDescriptors::kOther, 4, 40, -1);
   descriptors.AddDescriptor(4, 10, RawPcDescriptors::kOther, 5, 80, -1);
   descriptors.AddDescriptor(5, 80, RawPcDescriptors::kOther, 6, 150, -1);
 
   extern void GenerateIncrement(Assembler* assembler);
   Assembler _assembler_;
@@ skipping 1641 matching lines @@
   EXPECT_VALID(h_result);
   Integer& result = Integer::Handle();
   result ^= Api::UnwrapHandle(h_result);
   String& foo = String::Handle(String::New("foo"));
   Integer& expected = Integer::Handle();
   expected ^= foo.HashCode();
   EXPECT(result.IsIdenticalTo(expected));
 }
 
 }  // namespace dart