[api] Speed up template instantiation cache a bit.

src/bootstrapper.cc

Index: src/bootstrapper.cc
diff --git a/src/bootstrapper.cc b/src/bootstrapper.cc
index cb7c46a7d7a7d582291a458882c54fe165e37ab1..648931f8cbe09cd2058a9da31506010f4eba2141 100644
--- a/src/bootstrapper.cc
+++ b/src/bootstrapper.cc
@@ -2713,9 +2713,8 @@ bool Genesis::InstallNatives(GlobalContextType context_type) {
 
   if (!CallUtilsFunction(isolate(), "PostNatives")) return false;
 
-  auto template_instantiations_cache =
-      ObjectHashTable::New(isolate(), ApiNatives::kInitialFunctionCacheSize,
-                           USE_CUSTOM_MINIMUM_CAPACITY);
+  auto template_instantiations_cache = UnseededNumberDictionary::New(
+      isolate(), ApiNatives::kInitialFunctionCacheSize);
   native_context()->set_template_instantiations_cache(
       *template_instantiations_cache);