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

libmp: Fix trivial buffer overrun

fgetln yields a non-NUL-terminated buffer and its length. This routine
attempted to NUL-terminate it, but did not allocate space for the NUL. So,
allocate space for the NUL.

Reported by: Coverity
CID: 1017457
Sponsored by: EMC / Isilon Storage Division

Rename all symbols in libmp(3) to mp_*, just like Solaris.

The function pow() in libmp(3) clashes with pow(3) in libm. We could
rename this single function, but we can just take the same approach as
the Solaris folks did, which is to prefix all function names with mp_.

libmp(3) isn't really popular nowadays. I suspect not a single
application in ports depends on it. There's still a chance, so I've
increased the SHLIB_MAJOR and __FreeBSD_version.

Reviewed by: deischen, rdivacky

Pass BN_CTX to internal functions instead of allocating it internally.
This allows msqrt() to only call BN_CTX_new() once intead of many times.

Suggested and reviewed by: stefanf

Do not put BN_CTX structures on the stack, but instead allocate them
runtime using BN_CTX_new(). This is done since in OpenSSL 0.9.7e we
can only allocate BN_CTX on the stack by including an internal OpenSSL
header file, and in OpenSSL 0.9.8 BN_CTX is entirely opaque, so having
it on the stack is not possible at all.

This is done as preparation for OpenSSL 0.9.8b import.

Tested on: amd64 i386 ia64
Tested with: src/tools/regression/lib/libmp

Adjust for OpenSSL 0.9.7.

Add __FBSDID()s to libmp

This is the traditional BSD libmp interface implemented in terms of
the OpenSSL BIGNUM interface. It is provided for compatibility only
and should not be used in new code.