Fix known issues which blow up the process after dlopen("libthr.so")
(or loading a dso linked to libthr.so into process which was not
linked against threading library).

MFC r276630:
Remove interposing, fix malloc, reinstall signal handlers wrappers on
libthr load.

MFC r276681:
Avoid calling internal libc function through PLT or accessing data
though GOT.

MFC r277032:
Reduce the size of the interposing table and amount of
cancellation-handling code in the libthr.

MFC note:
r276646 ("do not erronously export 'openat' symbol from rtld") is not
applicable to stable/10 yet, since PATHFDS support was not merged.

MF9: Don't fail to build if MALLOC_PRODUCTION is defined in make.conf

- Remove debugging from GENERIC* kernel configurations
- Enable MALLOC_PRODUCTION
- Default dumpdev=NO
- Remove UPDATING entry regarding debugging features
- Bump __FreeBSD_version to 1000500

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

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

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

Update jemalloc to version 3.4.0.

Make the malloc(3) family of functions weak and make their non-weak
implementations visible for use by applications. The functions $F that
are now weak symbols are:
allocm, calloc, dallocm, free, malloc, malloc_usable_size,
nallocm, posix_memalign, rallocm, realloc, sallocm

The non-weak implementations of $F are exported as __$F.

Submitted by: stevek@juniper.net
Reviewed by: jasone@, kib@
Approved by: jasone@ (jemalloc)
Obtained from: juniper Networks, Inc

Import jemalloc 3.3.0. This reduces zeroed memory validation overhead for
non-MALLOC_PRODUCTION builds.

Import jemalloc 3.2.0.

Since our clang now supports the tls_model attribute, remove the
workaround for it in jemalloc_FreeBSD.h.

Reviewed by: jasone

Fix config_lazy_lock so that thread caching isn't used for
single-threaded applications.

Import jemalloc 3.0.0. This fixes memory zeroing bugs that manifested as
jemalloc assertion failures for debug builds, or as calloc() sometimes
returning non-zeroed memory for production builds.

Import jemalloc 37b6f95dcd866f51c91488531a2efc3ed4c2b754 (dev branch,
prior to 3.0.0 release). This version is likely very close to what will be
3.0.0.

jemalloc: pointer size definition for 64-bit mips platforms

LG_SIZEOF_PTR has to be defined as 3 when jemalloc is compiled for
64 bit platforms.

Reviewed by: juli
Approved by: jasone

Import jemalloc a8f8d7540d66ddee7337db80c92890916e1063ca (dev branch,
prior to 3.0.0 release). This fixes several bugs related to memory
initialization.

Mangle __jemalloc_a0{malloc,calloc,free}() just like all the other
library-internal symbols in jemalloc, and adjust the tls allocation code
in libc to use the mangled names.

Import jemalloc 606f1fdc3cdbc700717133ca56685313caea24bb (dev branch,
prior to 3.0.0 release), and mangle internal symbols.

Import jemalloc b57d3ec571c6551231be62b7bf92c084a8c8291c (dev branch,
prior to 3.0.0 release), which supports atomic operations based on atomic(9).
This should fix build failures for several platforms.

Import jemalloc 9ef7f5dc34ff02f50d401e41c8d9a4a928e7c2aa (dev branch,
prior to 3.0.0 release) as contrib/jemalloc, and integrate it into libc.
The code being imported by this commit diverged from
lib/libc/stdlib/malloc.c in March 2010, which means that a portion of
the jemalloc 1.0.0 ChangeLog entries are relevant, as are the entries
for all subsequent releases.