Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Fix warnings found by -Wmising-variable-declarations.

This self-written compiler warning, which is hopefully going to be
committed into LLVM sources soon, warns about potentially missing
`static' keywords, similar to -Wmissing-prototypes.

- bin/pax: Move external declaration of chdname and s_mask into extern.h.
- bin/setfacl: Move setfacl.c-specific stuff out of setfacl.h.
- sbin/mount_fusefs: Remove char *progname; use getprogname().
- others: add `static' where possible.

Change lwp to int64_t as thr_pread_long() always uses a 64-bit value
in order to account for LP64 targets when cross-debugging on ILP32,
allowing r224683 to compile on ILP32.
Note that thr_p{read,write}_{long,ptr}() still incorrectly use the size
of the respective types on the host rather than that on the target when
accessing the target address space which still needs to be fixed. This
means that r224683 alone may not be sufficient to solve the problem it's
intended to fix when cross-debugging.

Approved by: re (hrs)

The tid member of struct pthread actually is long so read it as such.
Accessing it as an int causes failure on big-endian LP64, i.e. mips64be,
powerpc64 and sparc64.

Reviewed by: marcel
Approved by: re (kib)
MFC after: 1 week

Extend the td_thrinfo_t to include siginfo for the signal that stopped
the target. Take care of ABI.

Suggested by: davidxu
MFC after: 2 weeks

Revert r181651, which changed the ABI, and use a temp variable instead.

Suggested by: attilio

Allow psaddr_t to be widened by using thr_pread_{int,long,ptr},
where critical. Some places still use ps_pread/ps_pwrite directly,
but only need changed when byte-order comes into the picture.
Also, change th_p in td_event_msg_t from a pointer type to
psaddr_t, so that events also work when psaddr_t is widened.

Cleanup for WARNS 6.

Change the type of psaddr_t from void* to uintptr_t. A pointer
type cannot be made wider to allow ILP32 platforms to target
LP64 platforms.

Use linker set to collection all target operations.

Fix return value.

Use ps_linfo to retrieve LWP info, current it is used to retrieve
signal mask and pending signals.

Always clear thread info buffer to zero.

Add support for XMM registers in GDB for x86 processors that support
SSE (or its successors).

Reviewed by: marcel, davidxu
MFC After: 2 weeks

Remove unused variables.

o Code cleanup, eliminate private thread id map, directly
use lwpid as thread id.
o Export tls pointer.

Fill traceme and events fields.

Sync with debugger code in libthr.

Export thread address.

Update debugger code for new libthr.

1. Add missing functions: libthr_dbresume,libthr_dbsuspend.
2. Implement functions: libthr_db_thr_setfpregs, libthr_db_thr_setregs,
libthr_db_ta_map_id2thr.
3. simplify libthr_db_thr_getfpregs, libthr_db_thr_getgregs.

Add rudimentary support and stubs for libthr and libc_r on alpha, amd64,
i386, ia64 and sparc64. Add stubs for alpha, amd64, ia64 and sparc64 for
libpthread.

Restructure the source files to avoid unnecessary use of subdirectories
that also force us to use non-portable compilation flags to deal with
the uncommon compilation requirements (building archive libraries for
linkage into a shared library).

The libpthread support has been copied from the original local and
cleaned-up to make them WARNS=2 clean.
that also force us to use non-portable compilation flags to deal with
the uncommon compilation requirements (building archive libraries for
linkage into a shared library).

The libpthread support has been copied from the original local and
cleaned-up to make them WARNS=2 clean.

Tested on: amd64, i386, ia64