custom_malloc.

A tiny and optimized custom allocator in pure C based on malloc

(Atm the better version is in the rework branch)...

TODO.

• Threading (need to be thread safe over pthread and MPI).
• Branching optimization and bin research.
• Security mitigations.
• Refine between SSE and AVX in block research.
• Improve the code structure.
• Maybe a garbage collector...