[Interpreter] Add support for local context loads and stores.

src/interpreter/bytecode-array-builder.h

Index: src/interpreter/bytecode-array-builder.h
diff --git a/src/interpreter/bytecode-array-builder.h b/src/interpreter/bytecode-array-builder.h
index 5f90f9ec7feebc921752e68eabdaa4c8c4ec1ed7..60b9765b54889d820047920f4d0bdee28baa79a2 100644
--- a/src/interpreter/bytecode-array-builder.h
+++ b/src/interpreter/bytecode-array-builder.h
@@ -30,19 +30,31 @@ class BytecodeArrayBuilder {
 
   // Set number of parameters expected by function.
   void set_parameter_count(int number_of_params);
-  int parameter_count() const;
+  int parameter_count() const {
+    DCHECK_GE(parameter_count_, 0);
+    return parameter_count_;
+  }
 
   // Set number of locals required for bytecode array.
   void set_locals_count(int number_of_locals);
-  int locals_count() const;
+  int locals_count() const {
+    DCHECK_GE(local_register_count_, 0);
+    return local_register_count_;
+  }
 
   // Set number of contexts required for bytecode array.
   void set_context_count(int number_of_contexts);
-  int context_count() const;
+  int context_count() const {
+    DCHECK_GE(context_register_count_, 0);
+    return context_register_count_;
+  }
 
   Register first_context_register() const;
   Register last_context_register() const;
 
+  // Returns the number of fixed (non-temporary) registers.
+  int fixed_register_count() const { return context_count() + locals_count(); }
+
   Register Parameter(int parameter_index) const;
 
   // Constant loads to the accumulator.
@@ -61,6 +73,9 @@ class BytecodeArrayBuilder {
   // Load the object at |slot_index| in |context| into the accumulator.
   BytecodeArrayBuilder& LoadContextSlot(Register context, int slot_index);
 
+  // Stores the object in the accumulator into |slot_index| of |context|.
+  BytecodeArrayBuilder& StoreContextSlot(Register context, int slot_index);
+
   // Register-accumulator transfers.
   BytecodeArrayBuilder& LoadAccumulatorWithRegister(Register reg);
   BytecodeArrayBuilder& StoreAccumulatorInRegister(Register reg);