FreeBSD_HEAD_i386 - Build #3177 - Fixed

FreeBSD_HEAD_i386 - Build #3177 - Fixed:

Build information: https://jenkins.FreeBSD.org/job/FreeBSD_HEAD_i386/3177/
Full change log: https://jenkins.FreeBSD.org/job/FreeBSD_HEAD_i386/3177/changes
Full build log: https://jenkins.FreeBSD.org/job/FreeBSD_HEAD_i386/3177/console

Change summaries:

300377 by pfg:
ndis(4): Avoid overflow.

This is a long standing problem: our random() function returns an
unsigned integer but the rand provided by ndis(4) returns an int.
Scale it down.

MFC after:	2 weeks

300376 by pfg:
ndis(4): Better mimic the behavior of rand() on Windows.

In ndis(4) we expose a rand() function that was constantly reseeding
with a time depending function every time it was called. This
essentially broke the reasoning behind seeding, and rendered srand()
a no-op.

Keep it simple, just use random() and srandom() as it's meant to work.
It  would have been tempting to just go for arc4random() but we
want to mimic Microsoft, and we don't need crypto-grade randomness
here.

PR:		209616
MFC after:	2 weeks

300375 by ian:
Adjust _ALIGNBYTES to the proper value for arm and armv6 arches.  Modern
compilers can emit arm instructions that require 8-byte alignment.  The
alignment-sensitive instructions were added in armv5, which has to be
supported by our combined v4/v5 kernels, so the value is set uncoditionally
for all arm architecture versions.

Also adjust the comment to explain in more detail why the macros have the
form and values they do.

Per advice from bde_at_, maintain the unsignedness of the value of _ALIGNBYTES
(but do so using his second choice of allowing sizeof() to supply the
unsignedness, rather than just hardcoding '8U', which in my mind would
require an even more verbose comment to explain why it's right).  Also
explain in the comment that the resulting type of _ALIGN() is equivelent
to uinptr_t on arm (32-bit unsigned int), but it's purposely spelled as
"unsigned" to avoid problems with including other header files.  Even
including machine/_types.h to allow use of __uintptr_t causes compilation
failures because of this header being included (indirectly) in asm code.

The discussion that led to this change (albeit at a glacial pace) is at
https://lists.freebsd.org/pipermail/svn-src-head/2014-November/064593.html

300374 by emaste:
elftoolchain: backwards compatability for ELFOSABI_CLOUDABI definition

It is not provided by sys/elf_common.h on older releases or -current
before March 2015.

Reported by:	Jenkins

300372 by avg:
fix loss of taskqueue wakeups (introduced in r300113)

Submitted by:	kmacy
Tested by:	dchagin