nptl: or1k, kvx: align the TLS block to struct pthread

tst-tls3 wants the initial thread's descriptor 16-byte aligned and got 8 on
or1k, so it aborted before doing anything else.

Both architectures are TLS_DTV_AT_TP with TLS_PRE_TCB_SIZE = sizeof (struct
pthread): the descriptor sits at the start of the allocated block and
THREAD_SELF hands it out. The block's alignment comes from TLS_TCB_ALIGN in
the dynamic case, through _dl_tls_static_align, and from TLS_INIT_TCB_ALIGN in
the static one, which __libc_setup_tls() takes as its max_align. These two
architectures are the only ones deriving either from tcbhead_t -- on or1k that
is a single pointer, so the alignment was 4 and the descriptor landed wherever
the allocator happened to put it. The other nineteen use
__alignof__ (struct pthread), which is what the object at that address needs.

Measured on or1k under qemu-or1k, printing pthread_self():

  dynamic   0x30810818  & 15 = 8    ->  0x30810820  & 15 = 0
  static    0x0001245c  & 15 = 12   ->  0x00012460  & 15 = 0

The static figure needed a separate build with HAVE_SHARED off, since
libc-tls.c is only compiled for binaries without a loader.

Full suite on or1k/6.1.53: 769 passed, 0 failed, 7 skipped -- was 768/1/7.

kvx gets the same change on the same reasoning, but is not measured: the probe
needs a libpthread-internal build and the toolchain's bundled sysroot is
threadless, so __alignof__ (struct pthread) could not be read out locally. The
change can only raise the alignment, never lower it, and kvx runs tst-tls3
under qemu, so a regression would show.

Signed-off-by: Ramin Moussavi <lordrasmus@gmail.com>

libpthread/nptl/sysdeps/kvx/tls.h

@@ -60,7 +60,7 @@ register tcbhead_t *__thread_self __asm__("$r13");
 # define TLS_INIT_TCB_SIZE	sizeof (tcbhead_t)
 
 /* Alignment requirements for the initial TCB.  */
-# define TLS_INIT_TCB_ALIGN	__alignof__ (tcbhead_t)
+# define TLS_INIT_TCB_ALIGN	__alignof__ (struct pthread)
 
 /* This is the size of the TCB.  */
 # define TLS_TCB_SIZE		sizeof (tcbhead_t)
@@ -69,7 +69,7 @@ register tcbhead_t *__thread_self __asm__("$r13");
 # define TLS_PRE_TCB_SIZE	sizeof (struct pthread)
 
 /* Alignment requirements for the TCB.  */
-# define TLS_TCB_ALIGN		__alignof__ (tcbhead_t)
+# define TLS_TCB_ALIGN		__alignof__ (struct pthread)
 
 /* Install the dtv pointer.  The pointer passed is to the element with
    index -1 which contain the length.  */

libpthread/nptl/sysdeps/or1k/tls.h

@@ -85,10 +85,10 @@ register tcbhead_t *__thread_self __asm__("r10");
 
 /* Requirements for the TCB.  */
 # define TLS_INIT_TCB_SIZE    sizeof (tcbhead_t)
-# define TLS_INIT_TCB_ALIGN   __alignof__ (tcbhead_t)
+# define TLS_INIT_TCB_ALIGN   __alignof__ (struct pthread)
 
 # define TLS_TCB_SIZE         sizeof (tcbhead_t)
-# define TLS_TCB_ALIGN        __alignof__ (tcbhead_t)
+# define TLS_TCB_ALIGN        __alignof__ (struct pthread)
 
 /* This is the size of the TCB.  */