Refactor AOT deduplication steps so they can run before an app-jit snapshot as well.

runtime/vm/compiler.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/compiler.h"
 
 #include "vm/assembler.h"
 
 #include "vm/ast_printer.h"
 #include "vm/block_scheduler.h"
@@ skipping 547 matching lines @@
               await_token_positions->At(i).FromSynthetic();
           if (!token_pos.IsReal()) {
             // Some async machinary uses sentinel values. Map them to
             // no source position.
             token_pos_value = Smi::New(TokenPosition::kNoSourcePos);
           } else {
             token_pos_value = Smi::New(token_pos.value());
           }
           await_to_token_map.SetAt(i, token_pos_value);
         }
-        code.SetAwaitTokenPositions(await_to_token_map);
+        code.set_await_token_positions(await_to_token_map);
       }
     }
   }
 #endif  // !defined(PRODUCT)
 
   if (!function.IsOptimizable()) {
     // A function with huge unoptimized code can become non-optimizable
     // after generating unoptimized code.
     function.set_usage_counter(INT_MIN);
   }
@@ skipping 1731 matching lines @@
 
 
 bool BackgroundCompiler::IsDisabled() {
   UNREACHABLE();
   return true;
 }
 
 #endif  // DART_PRECOMPILED_RUNTIME
 
 }  // namespace dart