const raw_c_allocator: Allocator = .{ .ptr = undefined, .vtable = raw_c_allocator_vtable };

Asserts allocations are within @alignOf(std.c.max_align_t) and directly calls malloc/free. Does not attempt to utilize malloc_usable_size. This allocator is safe to use as the backing allocator with ArenaAllocator for example and is more optimal in such a case than c_allocator.