[Builtins] Smi-check the spread and go to runtime in CheckSpreadAndPushToStack.

src/builtins/mips/builtins-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_MIPS
 
 #include "src/codegen.h"
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/full-codegen/full-codegen.h"
@@ skipping 2625 matching lines @@
   Register scratch = t0;
   Register scratch2 = t1;
 
   Register spread = a2;
   Register spread_map = t3;
 
   Register spread_len = t3;
 
   Register native_context = t4;
 
+  Label runtime_call, push_args;
   __ lw(spread, MemOperand(sp, 0));
+  __ JumpIfSmi(spread, &runtime_call);
   __ lw(spread_map, FieldMemOperand(spread, HeapObject::kMapOffset));
   __ lw(native_context, NativeContextMemOperand());
 
-  Label runtime_call, push_args;
   // Check that the spread is an array.
   __ lbu(scratch, FieldMemOperand(spread_map, Map::kInstanceTypeOffset));
   __ Branch(&runtime_call, ne, scratch, Operand(JS_ARRAY_TYPE));
 
   // Check that we have the original ArrayPrototype.
   __ lw(scratch, FieldMemOperand(spread_map, Map::kPrototypeOffset));
   __ lw(scratch2, ContextMemOperand(native_context,
                                     Context::INITIAL_ARRAY_PROTOTYPE_INDEX));
   __ Branch(&runtime_call, ne, scratch, Operand(scratch2));
 
@@ skipping 467 matching lines @@
     __ break_(0xCC);
   }
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_MIPS