sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

Adjust dtmalloc_unload() definition to avoid clang 15 warning

With clang 15, the following -Werror warnings is produced:

sys/cddl/dev/dtmalloc/dtmalloc.c:177:16: error: a function declaration without a prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]
dtmalloc_unload()
^
void

This is because dtmalloc_unload() is declared with a (void) argument
list, but defined with an empty argument list. Make the definition match
the declaration.

MFC after: 3 days

dtrace: remove /dev/dtrace/dtmalloc

It is unused.

Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D35379

malloc: move malloc_type_internal into malloc_type

According to code comments the original motivation was to allow for
malloc_type_internal changes without ABI breakage. This can be trivially
accomplished by providing spare fields and versioning the struct, as
implemented in the patch below.

The upshots are one less memory indirection on each alloc and disappearance
of mt_zone.

Reviewed by: markj
Differential Revision: https://reviews.freebsd.org/D27104

dtrace: depessimize dtmalloc when dtrace is active

Each malloc/free was testing dtrace_malloc_enabled and forcing
extra reads from the malloc type struct to see if perhaps a
dtmalloc probe was on.

Treat it like lockstat and sdt: have a global bolean.

Use C99 initializers for DTrace provider methods.

This makes the definitions easier to read and more cscope-friendly.

MFC after: 1 week

The dtmalloc provider uses the short description of a malloc type as the
function name of its corresponding DTrace probes. These descriptions may
contain whitespace, but probe names cannot, so just replace any whitespace
with underscores when creating probes.

MFC after: 1 week

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

- Import the HEAD csup code which is the basis for the cvsmode work.

Custom DTrace kernel module files plus FreeBSD-specific DTrace providers.