Remove support for lock elision.

The support for lock elision was already deprecated with glibc 2.42:
commit 77438db8cf
"Mark support for lock elision as deprecated."
See also discussions:
https://sourceware.org/pipermail/libc-alpha/2025-July/168492.html

This patch removes the architecture specific support for lock elision
for x86, powerpc and s390 by removing the elision-conf.h, elision-conf.c,
elision-lock.c, elision-timed.c, elision-unlock.c, elide.h, htm.h/hle.h files.
Those generic files are also removed.

The architecture specific structures are adjusted and the elision fields are
marked as unused.  See struct_mutex.h files.
Furthermore in struct_rwlock.h, the leftover __rwelision was also removed.
Those were originally removed with commit 0377a7fde6
"nptl: Remove rwlock elision definitions"
and by chance reintroduced with commit 7df8af43ad
"nptl: Add struct_rwlock.h"

The common code (e.g. the pthread_mutex-files) are changed back to the time
before lock elision was introduced with the x86-support:
- commit 1cdbe57948
"Add the low level infrastructure for pthreads lock elision with TSX"
- commit b023e4ca99
"Add new internal mutex type flags for elision."
- commit 68cc29355f
"Add minimal test suite changes for elision enabled kernels"
- commit e8c659d74e
"Add elision to pthread_mutex_{try,timed,un}lock"
- commit 49186d21ef
"Disable elision for any pthread_mutexattr_settype call"
- commit 1717da59ae
"Add a configure option to enable lock elision and disable by default"

Elision is removed also from the tunables, the initialization part, the
pretty-printers and the manual.

Some extra handling in the testsuite is removed as well as the full tst-mutex10
testcase, which tested a race while enabling lock elision.

I've also searched the code for "elision", "elide", "transaction" and e.g.
cleaned some comments.

I've run the testsuite on x86_64 and s390x and run the build-many-glibcs.py
script.
Thanks to Sachin Monga, this patch is also tested on powerpc.

A NEWS entry also mentions the removal.
Reviewed-by: Wilco Dijkstra  <Wilco.Dijkstra@arm.com>

sysdeps/nptl/bits/struct_mutex.h

@@ -21,8 +21,8 @@
 
 /* Generic struct for both POSIX and C11 mutexes.  New ports are expected
    to use the default layout, however architecture can redefine it to
-   add arch-specific extension (such as lock-elision).  The struct have
-   a size of 32 bytes on LP32 and 40 bytes on LP64 architectures.  */
+   add arch-specific extension.  The struct have a size of 32 bytes on LP32
+   and 40 bytes on LP64 architectures.  */
 
 struct __pthread_mutex_s
 {
@@ -40,21 +40,7 @@ struct __pthread_mutex_s
      PTHREAD_MUTEX_INITIALIZER or by a call to pthread_mutex_init.
 
      After a mutex has been initialized, the __kind of a mutex is usually not
-     changed.  BUT it can be set to -1 in pthread_mutex_destroy or elision can
-     be enabled.  This is done concurrently in the pthread_mutex_*lock
-     functions by using the macro FORCE_ELISION. This macro is only defined
-     for architectures which supports lock elision.
-
-     For elision, there are the flags PTHREAD_MUTEX_ELISION_NP and
-     PTHREAD_MUTEX_NO_ELISION_NP which can be set in addition to the already
-     set type of a mutex.  Before a mutex is initialized, only
-     PTHREAD_MUTEX_NO_ELISION_NP can be set with pthread_mutexattr_settype.
-
-     After a mutex has been initialized, the functions pthread_mutex_*lock can
-     enable elision - if the mutex-type and the machine supports it - by
-     setting the flag PTHREAD_MUTEX_ELISION_NP. This is done concurrently.
-     Afterwards the lock / unlock functions are using specific elision
-     code-paths.  */
+     changed.  BUT it can be set to -1 in pthread_mutex_destroy.  */
   int __kind;
 #if __WORDSIZE != 64
   unsigned int __nusers;