MFC r270650 (this is what should have been committed in r273497):

  Convert LIBCURSES to LIBNCURSES to fix "make checkdpadd"

  Also, add a missing LIBPANEL dependency for lldb

  Approved by: rpaulo (mentor)
  Suggested by: brooks
  Phabric: D675 (as part of a larger diff)
  PR: 192762
MFC r271365:

  Remove many false positives with make checkdpadd

  - Reduce DPADD and LDADD in checkdpadd to -l<foo>
  - Skip over -Wl,[es]*-group because -Wl,--end-group and
    -Wl,--start-group might be required to properly link objects (see
    usr.bin/clang/lldb as an example)

  This caveat has been present for a while with some components of
  the build. However, these false positives were made more more apparent
  after r269648.

  Phabric: D635
  Reviewed by: jmmv (an earlier version)
  PR: 192730
MFC r272055:

  Improve bsd.progs.mk compatibility with bsd.prog.mk

  1. Do not install FILES/SCRIPTS multiple times if PROGS is specified; this is
     already handled via bsd.prog.mk when it's called recursively (PR: 191055,
     191955).
  2. Some variables, like BINDIR and PROGNAME, default to a value if unset
     whereas others get appended to, like CFLAGS. Add support for the former case
     (PR: 191056)
  3. Make "checkdpadd" and "clean" available targets for recursive execution.

  Reviewed by: marcel, sjg
  Phabric: D822
  PR: 191055, 191056, 191955
  Sponsored by: EMC / Isilon Storage Division
MFC r271336:

  Expand the tests structure in test_small(..) to workaround the
  "initializer not constant" warning with gcc

  Approved by: jmmv (mentor)
  Phabric: D744
  Sponsored by: EMC / Isilon Storage Division
MFC r271349:

  Add diagnostic printfs and disable test # 4 on i386

  Reviewed by: jmmv, rpaulo
  Phabric: D749
  PR: 191676
  Sponsored by: EMC / Isilon Storage Division
MFC r272053:

  Have distrib-dirs, distribution, hier, hierarchy, redistribute, and reinstall
  depend on the .MAKE special target

  This will allow users to do something like the following to print out the
  results of the running the simulated make target with bmake, like some of the
  other top-level make targets in Makefile.inc1:

    % make -f Makefile.inc1 -n distribution TARGET=i386 TARGET_ARCH=i386

  Sponsored by: EMC / Isilon Storage Division
MFC r272917:

  Add LDFLAGS to PROG_VARS so it can be overridden on a per-PROG basis

  Sponsored by: EMC / Isilon Storage Division
MFC r272778:

  Set the autoindent to 4 spaces with vim in BSD.tests.dist

  This will prevent vim users from accidentally checking in buggy mtree files
  (mixed tabs/spaces).

  Sponsored by: EMC / Isilon Storage Division