Rename remaining linux32 symbols from linux_* to linux32_*.

289769:
Rename remaining linux32 symbols such as linux_sysent[] and
linux_syscallnames[] from linux_* to linux32_* to avoid conflicts with
linux64.ko.  While here, add support for linux64 binaries to systrace.
- Update NOPROTO entries in amd64/linux/syscalls.master to match the
  main table to fix systrace build.
- Add a special case for union l_semun arguments to the systrace
  generation.
- The systrace_linux32 module now only builds the systrace_linux32.ko.
  module on amd64.
- Add a new systrace_linux module that builds on both i386 and amd64.
  For i386 it builds the existing systrace_linux.ko.  For amd64 it
  builds a systrace_linux.ko for 64-bit binaries.

289822:
Fix build for the KTR-enabled kernels.

290143:
Fix build with DEBUG defined.

290144:
Update for LINUX32 rename.  The assembler didn't complain about undefined
symbols but just used 0 after the rename.

Ensure that all eight syscall arguments are available to dtrace_probe(),
rather than just the first five.

provider.  Previously we were erroneously supplying the argument types of
the corresponding entry probe.

Reviewed by:	rpaulo
MFC after:	1 week

Approved by: avg

Add systrace_linux32 and systrace_freebsd32 modules which provide
support for tracing compat system calls in addition to native system
call tracing provided by systrace module.

Provided that all the systrace modules are loaded now you can select
what syscalls to trace in the following manner:

syscall::xxx:yyy - work on all system calls that match the specification
syscall:freebsd:xxx:yyy - only native system calls
syscall:linux32:xxx:yyy - linux32 compat system calls
syscall:freebsd32:xxx:yyy - freebsd32 compat system calls on amd64

PR:		kern/152822
Submitted by:	Artem Belevich <fbsdlist@src.cx>
Reviewed by:	jhb (earlier version)
MFC after:	3 weeks

o uregs  (sson@)
o ustack (sson@)
o /dev/dtrace/helper device (needed for USDT probes)

The work done by me was:
Sponsored by:	The FreeBSD Foundation

Extend struct sysvec with three new elements:
sv_fetch_syscall_args - the method to fetch syscall arguments from
  usermode into struct syscall_args. The structure is machine-depended
  (this might be reconsidered after all architectures are converted).
sv_set_syscall_retval - the method to set a return value for usermode
  from the syscall. It is a generalization of
  cpu_set_syscall_retval(9) to allow ABIs to override the way to set a
  return value.
sv_syscallnames - the table of syscall names.

Use sv_set_syscall_retval in kern_sigsuspend() instead of hardcoding
the call to cpu_set_syscall_retval().

The new functions syscallenter(9) and syscallret(9) are provided that
use sv_*syscall* pointers and contain the common repeated code from
the syscall() implementations for the architecture-specific syscall
trap handlers.

Syscallenter() fetches arguments, calls syscall implementation from
ABI sysent table, and set up return frame. The end of syscall
bookkeeping is done by syscallret().

Take advantage of single place for MI syscall handling code and
implement ptrace_lwpinfo pl_flags PL_FLAG_SCE, PL_FLAG_SCX and
PL_FLAG_EXEC. The SCE and SCX flags notify the debugger that the
thread is stopped at syscall entry or return point respectively.  The
EXEC flag augments SCX and notifies debugger that the process address
space was changed by one of exec(2)-family syscalls.

The i386, amd64, sparc64, sun4v, powerpc and ia64 syscall()s are
changed to use syscallenter()/syscallret(). MIPS and arm are not
converted and use the mostly unchanged syscall() implementation.

Reviewed by:	jhb, marcel, marius, nwhitehorn, stas
Tested by:	marcel (ia64), marius (sparc64), nwhitehorn (powerpc),
	stas (mips)
MFC after:	1 month