[AArch64] Simplify getcontext pstate initialization.
[AArch64] Adjust elf_machine_dynamic to find _DYNAMIC via _GLOBAL_OFFSET_TABLE_
[BZ #15022] Correct global-scope dlopen issues in static executables.

This change creates a link map in static executables to serve as the
global search list for dlopen.  It fixes a problem with the inability
to access the global symbol object and a crash on an attempt to map a
DSO into the global scope.  Some code that has become dead after the
addition of this link map is removed too and test cases are provided.
Add a dlopen/getpagesize static executable test.
Support no-FPU ColdFire in sysdeps/m68k/fpu_control.h.
Fix sysdeps/m68k/fpu_control.h preprocessor indentation.
Mark packed structure element used with atomic operation aligned.
Test for mprotect failure in dl-load.c (bug 12492).
Consistently use page_shift in sysdeps/unix/sysv/linux/mmap64.c.
Add GLRO(dl_hwcap2) for new AT_HWCAP2 auxv_t a_type.
PowerPC: Define AT_HWCAP2 bits and AT_HWCAP2 handling for POWER8.
Skip SSE4.2 versions on Intel Silvermont

SSE2/SSSE3 versions are faster than SSE4.2 versions on Intel Silvermont.
Add more NEWS items for 2.18.
tile: switch to using <fenv.h> fallback functions

Now that the fallback functions match the desired semantics for tile
functions, just switch to using them.
Support no-FPU ColdFire in sysdeps/m68k/dl-trampoline.S and refactor code.
ARM: Pass dl_hwcap to IFUNC resolver functions.
Implement fma in soft-fp.
Enable static 32-bit SSE4.2 strcasecmp/strncasecmp
Add the low level infrastructure for pthreads lock elision with TSX

Lock elision using TSX is a technique to optimize lock scaling
It allows to run locks in parallel using hardware support for
a transactional execution mode in 4th generation Intel Core CPUs.
See http://www.intel.com/software/tsx for more Information.

This patch implements a simple adaptive lock elision algorithm based
on RTM. It enables elision for the pthread mutexes and rwlocks.
The algorithm keeps track whether a mutex successfully elides or not,
and stops eliding for some time when it is not.

When the CPU supports RTM the elision path is automatically tried,
otherwise any elision is disabled.

The adaptation algorithm and its tuning is currently preliminary.

The code adds some checks to the lock fast paths. Micro-benchmarks
show little to no difference without RTM.

This patch implements the low level "lll_" code for lock elision.
Followon patches hook this into the pthread implementation

Changes with the RTM mutexes:
-----------------------------
Lock elision in pthreads is generally compatible with existing programs.
There are some obscure exceptions, which are expected to be uncommon.
See the manual for more details.

- A broken program that unlocks a free lock will crash.
  There are ways around this with some tradeoffs (more code in hot paths)
  I'm still undecided on what approach to take here; have to wait for testing reports.
- pthread_mutex_destroy of a lock mutex will not return EBUSY but 0.
- There's also a similar situation with trylock outside the mutex,
  "knowing" that the mutex must be held due to some other condition.
  In this case an assert failure cannot be recovered. This situation is
  usually an existing bug in the program.
- Same applies to the rwlocks. Some of the return values changes
  (for example there is no EDEADLK for an elided lock, unless it aborts.
   However when elided it will also never deadlock of course)
- Timing changes, so broken programs that make assumptions about specific timing
  may expose already existing latent problems.  Note that these broken programs will
  break in other situations too (loaded system, new faster hardware, compiler
  optimizations etc.)
- Programs with non recursive mutexes that take them recursively in a thread and
  which would always deadlock without elision may not always see a deadlock.
  The deadlock will only happen on an early or delayed abort (which typically
  happens at some point)
  This only happens for mutexes not explicitely set to PTHREAD_MUTEX_NORMAL
  or PTHREAD_MUTEX_ADAPTIVE_NP.  PTHREAD_MUTEX_NORMAL mutexes do not elide.

The elision default can be set at configure time.

This patch implements the basic infrastructure for elision.
Add new internal mutex type flags for elision.

Add Enable/disable flags used internally

Extend the mutex initializers to have the fields needed for
elision. The layout stays the same, and this is not visible
to programs.

These changes are not exposed outside pthread