Revert "Add Smi::Zero and replace all Smi::FromInt(0) calls"

src/builtins/builtins-regexp.cc

 // Copyright 2016 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.
 
 #include "src/builtins/builtins-utils.h"
 #include "src/builtins/builtins.h"
 
 #include "src/code-factory.h"
 #include "src/regexp/jsregexp.h"
 
@@ skipping 304 matching lines @@
   typedef compiler::Node Node;
 
   Isolate* const isolate = a->isolate();
 
   Node* const receiver = a->Parameter(0);
   Node* const maybe_string = a->Parameter(1);
   Node* const context = a->Parameter(4);
 
   Node* const null = a->NullConstant();
   Node* const int_zero = a->IntPtrConstant(0);
-  Node* const smi_zero = a->SmiConstant(Smi::kZero);
+  Node* const smi_zero = a->SmiConstant(Smi::FromInt(0));
 
   // Ensure {receiver} is a JSRegExp.
   Node* const regexp_map = a->ThrowIfNotInstanceType(
       context, receiver, JS_REGEXP_TYPE, "RegExp.prototype.exec");
   Node* const regexp = receiver;
 
   // Check whether the regexp instance is unmodified.
   Node* const native_context = a->LoadNativeContext(context);
   Node* const regexp_fun =
       a->LoadContextElement(native_context, Context::REGEXP_FUNCTION_INDEX);
@@ skipping 567 matching lines @@
 BUILTIN(RegExpRightContextGetter) {
   HandleScope scope(isolate);
   const int start_index = GetLastMatchCapture(isolate, 1);
   Handle<String> last_subject = GetLastMatchSubject(isolate);
   const int len = last_subject->length();
   return *isolate->factory()->NewSubString(last_subject, start_index, len);
 }
 
 }  // namespace internal
 }  // namespace v8