Buck: host_info()

host_info()

This is liable to change in the future.

The host_info() function is used to get the current OS and processor architecture on the host. This will likely change as better cross compilation tooling comes to Buck. The structure returned is laid out thusly:
  struct(
      os=struct(
          is_linux=True|False,
          is_macos=True|False,
          is_windows=True|False,
          is_freebsd=True|False,
          is_unknown=True|False,
      ),
      arch=struct(
          is_aarch64=True|False,
          is_arm=True|False,
          is_armeb=True|False,
          is_i386=True|False,
          is_mips=True|False,
          is_mips64=True|False,
          is_mipsel=True|False,
          is_mipsel64=True|False,
          is_powerpc=True|False,
          is_ppc64=True|False,
          is_unknown=True|False,
          is_x86_64=True|False,
      ),
  )