Remove configure test for ARM TLS descriptors support.

GCC 4.7 added support for ARM TLS descriptors.  The binutils support
is present in binutils 2.22.  Thus, this patch removes the associated
configure test as obsolete (leaving Makefile conditionals, as NaCl
sets have-arm-tls-desc = no in its sysdeps fragment).

Tested for ARM that installed shared libraries are unchanged by the
patch.

	* sysdeps/arm/configure.ac (libc_cv_arm_tls_desc): Remove
	configure test.
	* sysdeps/arm/configure: Regenerated.
	* sysdeps/arm/Makefile [!have-arm-tls-desc] (have-arm-tls-desc):
	Define variable if not already defined.

4 files changed, 11 insertions, 49 deletions

diff --git a/ChangeLog b/ChangeLog
index a9a4ad088a..362b0aaea0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2015-10-27  Joseph Myers  <joseph@codesourcery.com>
 
+	* sysdeps/arm/configure.ac (libc_cv_arm_tls_desc): Remove
+	configure test.
+	* sysdeps/arm/configure: Regenerated.
+	* sysdeps/arm/Makefile [!have-arm-tls-desc] (have-arm-tls-desc):
+	Define variable if not already defined.
+
 	[BZ #17404]
 	* sysdeps/mips/atomic-machine.h
 	[__GNUC_PREREQ (4, 8) || (__mips16 && __GNUC_PREREQ (4, 7))]:
diff --git a/sysdeps/arm/Makefile b/sysdeps/arm/Makefile
index 17c129b2e1..2849aeda42 100644
--- a/sysdeps/arm/Makefile
+++ b/sysdeps/arm/Makefile
@@ -1,6 +1,11 @@
 gnulib-arch = $(elf-objpfx)libgcc-stubs.a
 static-gnulib-arch = $(elf-objpfx)libgcc-stubs.a
 
+# All supported build tools support TLS descriptors, but the OS may not.
+ifndef have-arm-tls-desc
+have-arm-tls-desc = yes
+endif
+
 ifeq ($(subdir),elf)
 sysdep-dl-routines += tlsdesc dl-tlsdesc
 sysdep_routines += aeabi_unwind_cpp_pr1 find_exidx
diff --git a/sysdeps/arm/configure b/sysdeps/arm/configure
index 87ec430da1..431e843b2b 100644
--- a/sysdeps/arm/configure
+++ b/sysdeps/arm/configure
@@ -176,42 +176,6 @@ else
 default-abi = soft"
 fi
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether the build tools support the GNU descriptor TLS scheme" >&5
-$as_echo_n "checking whether the build tools support the GNU descriptor TLS scheme... " >&6; }
-if ${libc_cv_arm_tls_desc+:} false; then :
-  $as_echo_n "(cached) " >&6
-else
-  old_CFLAGS="$CFLAGS"
-  CFLAGS="$CFLAGS -mtls-dialect=gnu2"
-  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-asm (".word\tfoo(tlsdesc)");
-int
-main ()
-{
-
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  libc_cv_arm_tls_desc=yes
-else
-  libc_cv_arm_tls_desc=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-  CFLAGS="$old_CFLAGS"
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_arm_tls_desc" >&5
-$as_echo "$libc_cv_arm_tls_desc" >&6; }
-if test $libc_cv_arm_tls_desc = yes; then
-  config_vars="$config_vars
-have-arm-tls-desc = yes"
-else
-  config_vars="$config_vars
-have-arm-tls-desc = no"
-fi
-
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether PC-relative relocs in movw/movt work properly" >&5
 $as_echo_n "checking whether PC-relative relocs in movw/movt work properly... " >&6; }
 if ${libc_cv_arm_pcrel_movw+:} false; then :
diff --git a/sysdeps/arm/configure.ac b/sysdeps/arm/configure.ac
index a9b114e3b9..90cdd69c75 100644
--- a/sysdeps/arm/configure.ac
+++ b/sysdeps/arm/configure.ac
@@ -26,19 +26,6 @@ else
   LIBC_CONFIG_VAR([default-abi], [soft])
 fi
 
-AC_CACHE_CHECK([whether the build tools support the GNU descriptor TLS scheme],
-  [libc_cv_arm_tls_desc],
-  [old_CFLAGS="$CFLAGS"
-  CFLAGS="$CFLAGS -mtls-dialect=gnu2"
-  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([asm (".word\tfoo(tlsdesc)");], [])],
-    [libc_cv_arm_tls_desc=yes], [libc_cv_arm_tls_desc=no])
-  CFLAGS="$old_CFLAGS"])
-if test $libc_cv_arm_tls_desc = yes; then
-  LIBC_CONFIG_VAR([have-arm-tls-desc], [yes])
-else
-  LIBC_CONFIG_VAR([have-arm-tls-desc], [no])
-fi
-
 AC_CACHE_CHECK([whether PC-relative relocs in movw/movt work properly],
 	       libc_cv_arm_pcrel_movw, [
 cat > conftest.s <<\EOF