Create a jitstd linked list

jitstd::list is a double linked list and we could be more efficient in terms of memory with a single linked list. The actual case where I could used is for for VariableLiveDescriptor, where I only need to insert at the back of the list and traverse it, but I guess we can have the need of a forward list too.

category:implementation theme:memory-usage skill-level:beginner cost:small