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

Rationalize BSD license on sys/*/include/float.h

Remove the advertising clause from the Regents of the University of
California's license, per the letter dated July 22, 1999.

Update clause numbering.

Add C11 macros describing subnormal numbers to float.h.

Reviewed by: bde

Add parentheses where required. Without them, `sizeof LDBL_MAX'
is a syntax error and shouldn't be, while `1 FLT_ROUNDS' isn't a
syntax error and should be. Thanks to bde for the examples.

Fix the definition of FLT_EVAL_METHOD and some minor bugs.

Implement FLT_ROUNDS for arm. Some (all?) arm FPUs lack support for
dynamic rounding modes, but FPUless chips that use softfloat can support it
because everything is emulated anyway. (We presently have incomplete
support for hardware FPUs.)

Submitted by: Ian Lepore

Bring in a version of float.h more correct for softfloat.

Start all license statements with /*-

Forced commit to note that the previous commit message doesn't apply
to the ARM port. We set FLT_ROUNDS to -1 (indeterminate), because the
rounding mode on ARM is static, i.e. part of the FP instruction
format. Or at least that's my understanding.

Make FLT_ROUNDS correctly reflect the dynamic rounding mode.

Import FreeBSD/arm kernel bits.
It only supports sa1110 (on simics) right now, but xscale support should come
soon.
Some of the initial work has been provided by :
Stephane Potvin <sepotvin at videotron.ca>
Most of this comes from NetBSD.