[Interpreter] Add CallRuntime support to the interpreter.

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 d68d5e7ffbf4b3860cfa985eb1d041732a799a8e..0377ab3cb6d160fa5e3fdb357e5d6376b9180d22 100644
--- a/src/interpreter/bytecode-array-builder.h
+++ b/src/interpreter/bytecode-array-builder.h
@@ -75,6 +75,12 @@ class BytecodeArrayBuilder {
   BytecodeArrayBuilder& Call(Register callable, Register receiver,
                              size_t arg_count);
 
+  // Call the runtime function with |function_id|. The first argument should be
+  // in |first_arg| and all subsequent arguments should be in registers \
+  // <first_arg + 1> to <first_arg + 1 + arg_count>.
+  BytecodeArrayBuilder& CallRuntime(Runtime::FunctionId function_id,
+                                    Register first_arg, size_t arg_count);
+
   // Operators (register == lhs, accumulator = rhs).
   BytecodeArrayBuilder& BinaryOperation(Token::Value binop, Register reg);