Remove support for pretenuring as it is not fully implemented and is currently turned on for a very…

runtime/lib/double.cc

Index: runtime/lib/double.cc
diff --git a/runtime/lib/double.cc b/runtime/lib/double.cc
index 2706269ad72e79bdb4f278f8f29c88640848e5fa..c28e1b1e0272b4eb687e859260abb63e9ae2e312 100644
--- a/runtime/lib/double.cc
+++ b/runtime/lib/double.cc
@@ -232,9 +232,7 @@ DEFINE_NATIVE_ENTRY(Double_parse, 3) {
 
 DEFINE_NATIVE_ENTRY(Double_toString, 1) {
   const Number& number = Number::CheckedHandle(arguments->NativeArgAt(0));
-  Heap::Space space = isolate->heap()->ShouldPretenure(kOneByteStringCid) ?
-      Heap::kPretenured : Heap::kNew;
-  return number.ToString(space);
+  return number.ToString(Heap::kNew);
 }