MFC r201815:

MFC r201815:

  To avoid hardcoding further kernel configuration names for
  make universe, split the logic into two parts:
  - 1st to build worlds and generate kernel configs like LINT.
  - 2nd to build kernels for a given TARGET architecture correctly
    finding all newly generated configs, not knowing anything about
    LINT anymore.

MFC rr201960:

  Use uname -m [1] and rename BUILD_ARCH to XMACHINE[2].

  Submitted by: nyan[1], imp[2]

MFC r202095:

  Rather than using an extra variable, only call uname if really needed and
  then directly assign the result.

  Submitted by: jmallett

git-svn-id: svn://svn.freebsd.org/base/stable/8@205747 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f