[regexp] Remove IsRegExp intrinsic

src/full-codegen/x64/full-codegen-x64.cc

Index: src/full-codegen/x64/full-codegen-x64.cc
diff --git a/src/full-codegen/x64/full-codegen-x64.cc b/src/full-codegen/x64/full-codegen-x64.cc
index bf1cc1a26c6f35bd83794a13e7db7da4daf8fc47..a19a68c2e88aec2f279d89c0e37716f0d2eb920d 100644
--- a/src/full-codegen/x64/full-codegen-x64.cc
+++ b/src/full-codegen/x64/full-codegen-x64.cc
@@ -1866,28 +1866,6 @@ void FullCodeGenerator::EmitIsTypedArray(CallRuntime* expr) {
 }
 
 
-void FullCodeGenerator::EmitIsRegExp(CallRuntime* expr) {
-  ZoneList<Expression*>* args = expr->arguments();
-  DCHECK(args->length() == 1);
-
-  VisitForAccumulatorValue(args->at(0));
-
-  Label materialize_true, materialize_false;
-  Label* if_true = NULL;
-  Label* if_false = NULL;
-  Label* fall_through = NULL;
-  context()->PrepareTest(&materialize_true, &materialize_false,
-                         &if_true, &if_false, &fall_through);
-
-  __ JumpIfSmi(rax, if_false);
-  __ CmpObjectType(rax, JS_REGEXP_TYPE, rbx);
-  PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-  Split(equal, if_true, if_false, fall_through);
-
-  context()->Plug(if_true, if_false);
-}
-
-
 void FullCodeGenerator::EmitIsJSProxy(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 1);