Add a new HashMap implementation

Adds a new, cleaned up, HashMap implementation.

* Uses Robin Hood Hashing (https://en.wikipedia.org/wiki/Hash_table#Robin_Hood_hashing).
* Keeps elements in a double linked list for simpler, ordered, iteration.
* Allows keeping iterators for later use in removal (Unlike Map<>, it does not do much
  for performance vs keeping the key, but helps replace old code).
* Uses a more modern C++ iterator API, deprecates the old one.
* Supports custom allocator (in case there is a wish to use a paged one).

This class aims to unify all the associative template usage and replace it by this one:
* Map<> (whereas key order does not matter, which is 99% of cases)
* HashMap<>
* OrderedHashMap<>
* OAHashMap<>

1 files changed, 2 insertions, 2 deletions

diff --git a/core/io/missing_resource.cpp b/core/io/missing_resource.cpp
index 7aae6c6f0a..29814cdeb3 100644
--- a/core/io/missing_resource.cpp
+++ b/core/io/missing_resource.cpp
@@ -53,8 +53,8 @@ bool MissingResource::_get(const StringName &p_name, Variant &r_ret) const {
 }
 
 void MissingResource::_get_property_list(List<PropertyInfo> *p_list) const {
-	for (OrderedHashMap<StringName, Variant>::ConstElement E = properties.front(); E; E = E.next()) {
-		p_list->push_back(PropertyInfo(E.value().get_type(), E.key()));
+	for (const KeyValue<StringName, Variant> &E : properties) {
+		p_list->push_back(PropertyInfo(E.value.get_type(), E.key));
 	}
 }