[interpreter] Add accumulator use description to bytecodes.

src/interpreter/interpreter-assembler.h

Index: src/interpreter/interpreter-assembler.h
diff --git a/src/interpreter/interpreter-assembler.h b/src/interpreter/interpreter-assembler.h
index bca3e034b3c4b4a02ca79685b0193efed054665b..8519b54620bf51ee660724f80aca9891891f06c8 100644
--- a/src/interpreter/interpreter-assembler.h
+++ b/src/interpreter/interpreter-assembler.h
@@ -150,9 +150,12 @@ class InterpreterAssembler : public compiler::CodeStubAssembler {
   void Abort(BailoutReason bailout_reason);
 
  protected:
+  Bytecode bytecode() const { return bytecode_; }
   static bool TargetSupportsUnalignedAccess();
 
  private:
+  // Returns the accumulator value without checking whether bytecode uses it.

[rmcilroy, 2016/04/05 12:59:23]

nit - mention it should only be used for passing accumulator value on dispatch
or for tracing. Also, I'd prefer if this was in a block of it's own (below these
4 methods).

[oth, 2016/04/05 14:12:10]

Done.

+  compiler::Node* GetAccumulatorUnchecked();
   // Returns a raw pointer to start of the register file on the stack.
   compiler::Node* RegisterFileRawPointer();
   // Returns a tagged pointer to the current function's BytecodeArray object.
@@ -217,6 +220,7 @@ class InterpreterAssembler : public compiler::CodeStubAssembler {
   Bytecode bytecode_;
   OperandScale operand_scale_;
   CodeStubAssembler::Variable accumulator_;
+  AccumulatorUse accumulator_use_;
   CodeStubAssembler::Variable context_;
   CodeStubAssembler::Variable bytecode_array_;