nx::mmap[unix]: Fix up use imports
nx::mmap[unix]: Fix some errors
nx::mmap[unix]: Fix some confusing error
nx::mmap[unix]: Make MapFile public
nx::mmap[unix]: Wrap unsafe calls in unsafe blocks
nx::mmap[unix]: Fix warnings emitted by rustc compiler
Reimplement full benchmark suite.

Signed-off-by: Peter Atashian <retep998@gmail.com>
Merge remote-tracking branch 'snake/fix-broken-posix'