[PATCH 4/7] nptl: x86_64: remove assembly implementation

[Adhemerval Zanella]

This patch removes the x86_64 assembly implementation for
pthread_cond_timedwait, pthread_cond_wait, sem_timedwait, and sem_wait
for upcoming BZ#12683 fix.  The fix require that cancellable futex calls
to be called through __syscall_cancel.

Although it not strictly require, the remove of the x86_64 specific
implementation follows the rationale:

1. The adjustments required to this fix is extensive (parameters
   save, functions calls, etc.) and there is little gain in keep an
   alternate implementation for x86_64 in term of maintanability.
2. There is no pthread_cond benchmark that shows these implementations
   are more 'optimized' that what current compilers can produce using
   generic C code.
3. The changes required also can change the exact gains this optimized is
   intended to provide.

Tested on x86_64.

--

	* sysdeps/unix/sysv/linux/x86_64/cancellation.S: Remove file.
	* sysdeps/unix/sysv/linux/x86_64/libc-cancellation.S: Remove file.
	* sysdeps/unix/sysv/linux/x86_64/librt-cancellation.S: Remove file.
	* sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S: Remove

--

diff --git a/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S b/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S
deleted file mode 100644
index 0dc2340..0000000
--- a/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S
+++ /dev/null
diff --git a/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S b/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S
deleted file mode 100644
index 0e61d0a..0000000
--- a/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S
+++ /dev/null
diff --git a/sysdeps/unix/sysv/linux/x86_64/sem_timedwait.S b/sysdeps/unix/sysv/linux/x86_64/sem_timedwait.S
deleted file mode 100644
index 880610e..0000000
--- a/sysdeps/unix/sysv/linux/x86_64/sem_timedwait.S
+++ /dev/null
diff --git a/sysdeps/unix/sysv/linux/x86_64/sem_wait.S b/sysdeps/unix/sysv/linux/x86_64/sem_wait.S
deleted file mode 100644
index 8f4d068..0000000
--- a/sysdeps/unix/sysv/linux/x86_64/sem_wait.S
+++ /dev/null