[Interpreter] Adds support for rest parameters to interpreter.

src/interpreter/bytecode-array-builder.cc

Index: src/interpreter/bytecode-array-builder.cc
diff --git a/src/interpreter/bytecode-array-builder.cc b/src/interpreter/bytecode-array-builder.cc
index 4a1602a1d6ea6c3749cc74b30111c53a4cd1e730..6387cdae9d6145ba819ab07e62e14503f8380481 100644
--- a/src/interpreter/bytecode-array-builder.cc
+++ b/src/interpreter/bytecode-array-builder.cc
@@ -606,6 +606,16 @@ BytecodeArrayBuilder& BytecodeArrayBuilder::CreateArguments(
   return *this;
 }
 
+BytecodeArrayBuilder& BytecodeArrayBuilder::CreateRestArguments(int index) {
+  size_t index_entry =
+      GetConstantPoolEntry(Handle<Object>(Smi::FromInt(index), isolate_));
+  // This will always be the first entry in the constant pool, since the rest
+  // arguments object is created at the start of the function just after
+  // creating the arguments object.
+  CHECK(FitsInIdx8Operand(index_entry));
+  Output(Bytecode::kCreateRestArguments, static_cast<uint8_t>(index_entry));
+  return *this;
+}
 
 BytecodeArrayBuilder& BytecodeArrayBuilder::CreateRegExpLiteral(
     Handle<String> pattern, int literal_index, int flags) {