ext2fs: fix a bug in dirindex and re-enable.

The IN_* flags should be set in i_flag instead of corrupting
i_flags [1].

Re-enable HTree dirindex as the last series of bug fixes
seems to have fixed the issues.

Reported by:	bde [1]
Tested by:	kevlo
MFC after:	1 week
sh: Add test for nested alias.
dtrace: remove unexplained 16MB limitation from dt_alloc/dt_zalloc

The limitation was introduced in r178556 without any note or comment.
It seems pretty artificial and now it leads to problems like the following:
  $ dtrace -x bufsize=17m -n ...
  dtrace: processing aborted: Memory allocation failure
OpenSolaris and illumos never had this limitation.

Sponsored by:	HybridCluster
Hide now harmless warning from dmesg.

MFC after:	1 week
Fix comment.
sh: Solve the alias recursion problem in a less hackish way.

Add the space to avoid alias recursion when the alias is expanded, not when
it is added.

As a result, displaying an alias via command -v, command -V or type no
longer erroneously appends a space. Adjust the tests so they now require
this bug to be absent.
Remove redundant declaration for uart devclass.
Commint some unrelated, but harmless, FDT ifdefs.
Add NAND support
Fix comment
This board has 4 wire support
Fix comment to match option
Fix comment to match option
Fix comment to match option
Remove obsolete option
Fix the build so -DNO_TESTS is passed in various phases that don't
require tests in order to build or install.  Crucially, don't try to
install tests during the lib32 install phase.  This commit supersedes
r261081, which fixed the lib32 install phase problem, but didn't fix
other phases.

Submitted by:	Garrett Cooper
Reviewed by:	sjg
MFC after:	13 days
Fix the Makefiles so that the tests I submitted in r261081 will actually
get built.

Sponsored by:	Spectra Logic
MFC after:	13 days
X-MFC-With:	r261081
Add more USB quirks.

Submitted by:	Gerrit Kuehn <gerrit.kuehn@aei.mpg.de>
MFC after:	1 week
In an effort to diagnose possible corruption of struct vm_page on some
sparc64 machines make the page queue assert in vm_page_dequeue() more
precise.  While I'm here switch the page lock assert to the newer style.