[arm] Share constant pool entries in snapshot.

src/interpreter/setup-interpreter-internal.cc

 // Copyright 2017 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/interpreter/setup-interpreter.h"
 
 #include "src/handles-inl.h"
 #include "src/interpreter/bytecodes.h"
 #include "src/interpreter/interpreter-generator.h"
 #include "src/interpreter/interpreter.h"
 #include "src/objects-inl.h"
 
 namespace v8 {
 namespace internal {
 namespace interpreter {
 
 // static
 void SetupInterpreter::InstallBytecodeHandlers(Interpreter* interpreter) {
   DCHECK(!interpreter->IsDispatchTableInitialized());
   HandleScope scope(interpreter->isolate_);
+  CanonicalHandleScope canonical(interpreter->isolate_);

[rmcilroy, 2017/05/16 09:04:05]

Why is this needed? Could you add a comment please.

   Address* dispatch_table = interpreter->dispatch_table_;
 
   // Generate bytecode handlers for all bytecodes and scales.
   const OperandScale kOperandScales[] = {
 #define VALUE(Name, _) OperandScale::k##Name,
       OPERAND_SCALE_LIST(VALUE)
 #undef VALUE
   };
 
   for (OperandScale operand_scale : kOperandScales) {
@@ skipping 51 matching lines @@
   if (ReuseExistingHandler(dispatch_table, bytecode, operand_scale)) return;
 
   size_t index = Interpreter::GetDispatchTableIndex(bytecode, operand_scale);
   Handle<Code> code = GenerateBytecodeHandler(isolate, bytecode, operand_scale);
   dispatch_table[index] = code->entry();
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8