[Interpreter] Add support for JS calls.

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 d4e1c34e540a2d67a22c19d61c7372c78dbf6cfb..e84f16ea721dd8db6b31e0f969730a20ab68a4e2 100644
--- a/src/interpreter/bytecode-array-builder.h
+++ b/src/interpreter/bytecode-array-builder.h
@@ -56,6 +56,11 @@ class BytecodeArrayBuilder {
   BytecodeArrayBuilder& LoadKeyedProperty(Register object, int feedback_slot,
                                           LanguageMode language_mode);
 
+  // Call JS function. The function to be called should be in the accumulator
+  // and all arguments (including the receiver) should be in registers
+  // <first_arg> to <first_arg + count>.
+  BytecodeArrayBuilder& CallJS(Register first_arg, size_t arg_count);
+
   // Operators.
   BytecodeArrayBuilder& BinaryOperation(Token::Value binop, Register reg);