faux_alloc vs one_alloc vs alloc-no-stdlib

A fake 'allocator'

A custom allocator that allows a singular allocation of a specific size known ahead of time.

A dynamic allocator that may be used with or without the stdlib. This allows a package with nostd to allocate memory dynamically and be used either with a custom allocator, items on the stack, or by a package that wishes to simply use Box<>. It also provides options to use calloc or a mutable global variable for pre-zeroed memory