First step in reducing the size of PC descriptors.

runtime/vm/flow_graph_builder.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 "vm/flow_graph_builder.h"
 
 #include "lib/invocation_mirror.h"
 #include "vm/ast_printer.h"
 #include "vm/bit_vector.h"
 #include "vm/class_finalizer.h"
@@ skipping 91 matching lines @@
     ASSERT(owner_->nesting_stack_ == this);
     owner_->nesting_stack_ = outer_;
   }
 
  private:
   FlowGraphBuilder* owner_;
   const SourceLabel* label_;
   NestedStatement* outer_;
 
   JoinEntryInstr* break_target_;
-  intptr_t try_index_;
+  const intptr_t try_index_;
 };
 
 
 intptr_t NestedStatement::ContextLevel() const {
   // Context level is determined by the innermost nested statement having one.
   return (outer() == NULL) ? 0 : outer()->ContextLevel();
 }
 
 
 intptr_t FlowGraphBuilder::context_level() const {
@@ skipping 3875 matching lines @@
           LanguageError::kBailout,
           Heap::kNew,
           "FlowGraphBuilder Bailout: %s %s",
           String::Handle(I, function.name()).ToCString(),
           reason));
   I->long_jump_base()->Jump(1, error);
   UNREACHABLE();
 }
 
 }  // namespace dart