Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Stop building vers.c in include/ and only build the needed osreldate.h.

Because of how osreldate.h was being built with newvers.sh, which always
spat out a vers.c dependent on SVN or git, the meta mode build was
considering osreldate.h to depend on the current git or SVN index. This
would lead to entire tree rebuilds when modifying git's index. There's
no reason to be generating vers.c here so just skip it.

While here, in mk-osreldate.sh rename PARAM_H to proper PARAMFILE (which
newvers.sh already has a default for) and remove unneeded export.

Sponsored by: EMC / Isilon Storage Division

Misc fixes from projects/bmake

Differential Revision: D2748
Reviewed by: brooks imp

Set proper permissions on the generated osreldate.h file; a file readable
only by root can cause install problems, especially over nfs.

Submitted by: jilles@
Approved by: re (gjb)

Prevent the set -e from mk-osreldate.sh from propagating into newvers.sh.
This would cause detection of old versions of SVN to cause fatal errors
instead of being caught and handled, which would make the build fail if
the tree had been checked out with an older version of SVN (e.g. 1.6).

Discussed with: gjb
Approved by: re (marius)

Create a separate script to generate osreldate.h rather than sourcing
newvers.sh into a temporary subshell with inline make rules.

Using a separate script fixes a variety of problems, including establishing
the correct dependencies in the makefiles. It also eliminates a problem
with the way newvers.sh uses `realpath $0`, because $0 expands differently
within a script sourced into a rule in a makefile depending on the version
of make and of /bin/sh being used. The latter can cause build breakage in a
cross-build environment, and can also make it difficult to compile 10.0 on
older pre-10.0 systems.

PR: 160646 174422
Submitted by: Garrett Cooper <yaneurabeya@gmail.com>
Approved by: re (gjb)
MFC after: 2 weeks