MIPS: ES6 symbols: Implement Symbol intrinsic and basic functionality

src/mips/stub-cache-mips.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2413 matching lines @@
       __ GetObjectType(a1, a3, a3);
       __ Branch(&miss, Ugreater_equal, a3, Operand(FIRST_NONSTRING_TYPE));
       // Check that the maps starting from the prototype haven't changed.
       GenerateDirectLoadGlobalFunctionPrototype(
           masm(), Context::STRING_FUNCTION_INDEX, a0, &miss);
       CheckPrototypes(
           Handle<JSObject>(JSObject::cast(object->GetPrototype(isolate()))),
           a0, holder, a3, a1, t0, name, &miss);
       break;
 
+    case SYMBOL_CHECK:
+      // Check that the object is a symbol.
+      __ GetObjectType(a1, a1, a3);
+      __ Branch(&miss, ne, a3, Operand(SYMBOL_TYPE));
+      break;
+
     case NUMBER_CHECK: {
       Label fast;
       // Check that the object is a smi or a heap number.
       __ JumpIfSmi(a1, &fast);
       __ GetObjectType(a1, a0, a0);
       __ Branch(&miss, ne, a0, Operand(HEAP_NUMBER_TYPE));
       __ bind(&fast);
       // Check that the maps starting from the prototype haven't changed.
       GenerateDirectLoadGlobalFunctionPrototype(
           masm(), Context::NUMBER_FUNCTION_INDEX, a0, &miss);
@@ skipping 1667 matching lines @@
     __ Jump(ic_slow, RelocInfo::CODE_TARGET);
   }
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_MIPS