[Interpreter] Add support for JS calls.

src/compiler/interpreter-assembler.h

Index: src/compiler/interpreter-assembler.h
diff --git a/src/compiler/interpreter-assembler.h b/src/compiler/interpreter-assembler.h
index 0949fbb5e6c5a9f824934741b2f590865373626b..adb7ed8f71971bb9a5f94cf5c39eac12929c9a42 100644
--- a/src/compiler/interpreter-assembler.h
+++ b/src/compiler/interpreter-assembler.h
@@ -38,7 +38,10 @@ class InterpreterAssembler {
 
   Handle<Code> GenerateCode();
 
-  // Returns the Idx immediate for bytecode operand |operand_index| in the
+  // Returns the count immediate for bytecode operand |operand_index| in the
+  // current bytecode.
+  Node* BytecodeOperandCount(int operand_index);
+  // Returns the index immediate for bytecode operand |operand_index| in the
   // current bytecode.
   Node* BytecodeOperandIdx(int operand_index);
   // Returns the Imm8 immediate for bytecode operand |operand_index| in the
@@ -56,6 +59,10 @@ class InterpreterAssembler {
   Node* LoadRegister(Node* reg_index);
   Node* StoreRegister(Node* value, Node* reg_index);
 
+  // Returns the location in memory of the register |reg_index| in the
+  // interpreter register file.
+  Node* RegisterLocation(Node* reg_index);
+
   // Constants.
   Node* Int32Constant(int value);
   Node* IntPtrConstant(intptr_t value);
@@ -66,6 +73,11 @@ class InterpreterAssembler {
   Node* SmiTag(Node* value);
   Node* SmiUntag(Node* value);
 
+  // Basic arithmetic operations.
+  Node* IntPtrAdd(Node* a, Node* b);
+  Node* IntPtrSub(Node* a, Node* b);
+  Node* WordShl(Node* value, int shift);
+
   // Load constant at |index| in the constant pool.
   Node* LoadConstantPoolEntry(Node* index);
 
@@ -81,6 +93,10 @@ class InterpreterAssembler {
   // Load the TypeFeedbackVector for the current function.
   Node* LoadTypeFeedbackVector();
 
+  // Call JSFunction or Callable |function| with |arg_count| (not including
+  // receiver) and the first argument located at |first_arg|.
+  Node* CallJS(Node* function, Node* first_arg, Node* arg_count);
+
   // Call an IC code stub.
   Node* CallIC(CallInterfaceDescriptor descriptor, Node* target, Node* arg1,
                Node* arg2, Node* arg3, Node* arg4);