V1.0: Recursive scan

v1.1: Collects more metadata

v2.0: Multi threaded scan

v2.1: Uses AVX2 instead of SSE2

v3.0: Simple mutex/critical section based MPMC queue

v3.1: Lock free MPMC queue Vyukov-style

v3.2: Making the lock free MPMC queue growable
Add padding to avoir false sharing
Add sleep() and SwitchToThread() to limit spinning

v3.3: Fix bug slots used before initialization,compare and swap is protecting updating committed, but it is not protecting the memory initialization. Adding atomic_flag commit_lock to protect against that
Fix bug multiple threads committing at the same time, fixed by using atomic_flag commit_lock and re-checking committed after acquiring the lock
Reorder helper functions

v3.4: Rewriting hash_worker() to export file_hashes.txt

3.5: Instead of writing directly to file_hashes.txt, hash_workers now are using a local arena, writing everything once at the end
Using #pragma once to ensure that a given header file is included only once in a single compilation unit
Forcing xxhash to use the stack instead of the heap
Making the hashing buffer reusable instead of malloc every file
Implementing a general purpose arena to replace small allocations
Small improvements of the LF MPMC queue
Making the LF MPMC queue generic and in a seperate header file