Keep zone cached in SnapshotReader to allow removing ZoneHandle(Isolate*) interface.

runtime/vm/flow_graph_inliner.cc

 // Copyright (c) 2013, 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_inliner.h"
 
 #include "vm/block_scheduler.h"
 #include "vm/compiler.h"
 #include "vm/flags.h"
 #include "vm/flow_graph.h"
@@ skipping 975 matching lines @@
       if ((constant != NULL) && constant->HasUses()) {
         constant->ReplaceUsesWith(
             caller_graph_->GetConstant(constant->value()));
       }
       CurrentContextInstr* context = (*defns)[i]->AsCurrentContext();
       if ((context != NULL) && context->HasUses()) {
         ASSERT(call->IsClosureCall());
         LoadFieldInstr* context_load = new(Z) LoadFieldInstr(
             new Value((*arguments)[0]->definition()),
             Closure::context_offset(),
-            AbstractType::ZoneHandle(isolate(), AbstractType::null()),
+            AbstractType::ZoneHandle(zone(), AbstractType::null()),
             call_data->call->token_pos());
         context_load->set_is_immutable(true);
         context_load->set_ssa_temp_index(
             caller_graph_->alloc_ssa_temp_index());
         context_load->InsertBefore(callee_entry->next());
         context->ReplaceUsesWith(context_load);
       }
     }
 
     // Check that inlining maintains use lists.
@@ skipping 422 matching lines @@
     if ((constant != NULL) && constant->HasUses()) {
       constant->ReplaceUsesWith(
           owner_->caller_graph()->GetConstant(constant->value()));
     }
     CurrentContextInstr* context = (*defns)[i]->AsCurrentContext();
     if ((context != NULL) && context->HasUses()) {
       ASSERT(call_data.call->IsClosureCall());
       LoadFieldInstr* context_load = new(Z) LoadFieldInstr(
           new Value(redefinition),
           Closure::context_offset(),
-          AbstractType::ZoneHandle(isolate(), AbstractType::null()),
+          AbstractType::ZoneHandle(zone(), AbstractType::null()),
           call_data.call->token_pos());
       context_load->set_is_immutable(true);
       context_load->set_ssa_temp_index(
           owner_->caller_graph()->alloc_ssa_temp_index());
       context_load->InsertAfter(redefinition);
       context->ReplaceUsesWith(context_load);
     }
   }
   return true;
 }
@@ skipping 426 matching lines @@
 intptr_t FlowGraphInliner::NextInlineId(const Function& function,
                                         intptr_t parent_id) {
   const intptr_t id = inline_id_to_function_->length();
   inline_id_to_function_->Add(&function);
   caller_inline_id_->Add(parent_id);
   return id;
 }
 
 
 }  // namespace dart