Revert of [regexp] Remove IsRegExp intrinsic

src/crankshaft/hydrogen.cc

 // Copyright 2013 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/crankshaft/hydrogen.h"
 
 #include <memory>
 #include <sstream>
 
 #include "src/allocation-site-scopes.h"
@@ skipping 11925 matching lines @@
 void HOptimizedGraphBuilder::GenerateIsTypedArray(CallRuntime* call) {
   DCHECK(call->arguments()->length() == 1);
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
   HValue* value = Pop();
   HHasInstanceTypeAndBranch* result =
       New<HHasInstanceTypeAndBranch>(value, JS_TYPED_ARRAY_TYPE);
   return ast_context()->ReturnControl(result, call->id());
 }
 
 
+void HOptimizedGraphBuilder::GenerateIsRegExp(CallRuntime* call) {
+  DCHECK(call->arguments()->length() == 1);
+  CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
+  HValue* value = Pop();
+  HHasInstanceTypeAndBranch* result =
+      New<HHasInstanceTypeAndBranch>(value, JS_REGEXP_TYPE);
+  return ast_context()->ReturnControl(result, call->id());
+}
+
+
 void HOptimizedGraphBuilder::GenerateToInteger(CallRuntime* call) {
   DCHECK_EQ(1, call->arguments()->length());
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
   HValue* input = Pop();
   if (input->type().IsSmi()) {
     return ast_context()->ReturnValue(input);
   } else {
     Callable callable = CodeFactory::ToInteger(isolate());
     HValue* stub = Add<HConstant>(callable.code());
     HValue* values[] = {input};
@@ skipping 1045 matching lines @@
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 }  // namespace internal
 }  // namespace v8