Optimize AOT's switchable calls for the monomorphic case.

runtime/vm/disassembler_ia32.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/disassembler.h"
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_IA32.
 #if defined(TARGET_ARCH_IA32)
 #include "platform/utils.h"
 #include "vm/allocation.h"
@@ skipping 1798 matching lines @@
   }
   hex_buffer[hex_index] = '\0';
   if (out_instr_len) {
     *out_instr_len = instruction_length;
   }
 
   *object = NULL;
   if (!code.IsNull() && code.is_alive()) {
     intptr_t offsets_length = code.pointer_offsets_length();
     for (intptr_t i = 0; i < offsets_length; i++) {
-      uword addr = code.GetPointerOffsetAt(i) + code.EntryPoint();
+      uword addr = code.GetPointerOffsetAt(i) + code.PayloadStart();
       if ((pc <= addr) && (addr < (pc + instruction_length))) {
         *object = &Object::Handle(*reinterpret_cast<RawObject**>(addr));
         break;
       }
     }
   }
 }
 
 #endif  // !PRODUCT
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32