binmiscctl.8: Remove a double word

- s/the the/the/

MFC after: 3 days

Remove $FreeBSD$: two-line nroff pattern

Remove /^\.\\"\n\.\\"\s*\$FreeBSD\$$\n/

imgact_binmisc: Optionally pre-open the interpreter vnode

This allows the use of chroot and/or jail environments which depend on
interpreters registed with imgact_binmisc to use emulator binaries from
the host to emulate programs inside the chroot.

Reviewed by: imp
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D37432

Add RISC-V interpreter example

Now that RISC-V support has landed in qemu-user-static, add to the list
of examples in the binmiscctl(8) manpage.

Reviewed by: kevans
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D24646

Remove sparc64 example.

Reivewed by: cy@, bcr@
Differential Revision: https://reviews.freebsd.org/D23593

Improve the binmiscctl manual page

- Use "Fl -" instead of "Cm --" for long options.
- Sort options alphabetically.
- Pet "mandoc -Tlint".
- Clean up the description of the "--interpreter" option.
- Clean up the description of the first example in the examples section.
- Use ".Bd -literal -offset indent" for all example code blocks for consistency.
- Use "Nm" instead of "Cm binmiscctl".
- Indent all examples for consistency.

Reviewed by: allanjude
Approved by: mat (mentor)
Differential Revision: https://reviews.freebsd.org/D15589

Correct the binmiscctl(8) man page for powerpc64

Magic for powerpc64 erroneously specified ELFCLASS32 instead of ELFCLASS64.

Submitted by: luca.pizzamiglio _AT_ gmail DOT com
MFC after: 3 days

Add example for upcoming aarch64/arm64 targets.

Move the explanation for examples before the example itself. Add
numerous QEMU examples and explanations supplied by sbruno, with thanks
to Ingo Schwarze for help with the mdoc markup. Code, text, testing,
proofreading, cinematography, stunts, and the haunting theme song
supplied by sbruno.

Submitted by: sbruno
Reviewed by: sbruno
MFC after: 1 week

mdoc: kill EOL whitespace.

mdoc: use display block in the beginning of the EXAMPLES section.

More mdoc/spelling/grammar cleanup.

Quick mdoc/whitespace/spelling pass, this needs some more work.

Add Stacey Son's binary activation patches that allow remapping of
execution to a emumation program via parsing of ELF header information.

With this kernel module and userland tool, poudriere is able to build
ports packages via the QEMU userland tools (or another emulator program)
in a different architecture chroot, e.g. TARGET=mips TARGET_ARCH=mips

I'm not connecting this to GENERIC for obvious reasons, but this should
allow the kernel module to be built by default and enable the building
of the userland tool (which automatically loads the kernel module).

Submitted by: sson@
Reviewed by: jhb@