[Interpreter] Add support for JS calls.

src/interpreter/interpreter.cc

Index: src/interpreter/interpreter.cc
diff --git a/src/interpreter/interpreter.cc b/src/interpreter/interpreter.cc
index 334f7d3eaf56bd9262d18b2551cf0ee20c4d8c01..f24bda0c19fb4c2d1d78c7cfb80e54233630b197 100644
--- a/src/interpreter/interpreter.cc
+++ b/src/interpreter/interpreter.cc
@@ -282,6 +282,24 @@ void Interpreter::DoMod(compiler::InterpreterAssembler* assembler) {
 }
 
 
+// CallJS <first_arg_reg> <arg_count>
+//
+// Call a JS function with arguments in registers <first_arg_reg> to
+// <first_arg_reg + arg_count>. The JSfunction or Callable to call is in
+// the accumulator.
+void Interpreter::DoCallJS(compiler::InterpreterAssembler* assembler) {
+  Node* first_arg_reg_index = __ BytecodeOperandReg(0);
+  Node* first_arg = __ RegisterLocation(first_arg_reg_index);
+  Node* args_count = __ BytecodeOperandCount(1);
+  Node* args_size = __ WordShl(args_count, kPointerSizeLog2);
+  Node* last_arg = __ IntPtrSub(first_arg, args_size);
+  Node* function = __ GetAccumulator();
+  Node* result = __ CallJS(function, first_arg, last_arg);
+  __ SetAccumulator(result);
+  __ Dispatch();
+}
+
+
 // Return
 //
 // Return the value in register 0.