require tls_runtime for tls execution test

All TLS execution tests require tls_runtime, not just tls; pr78796.c
is the only exception that is not otherwise limited to platforms known
to support it.  I suppose that's an oversight.  On a platform whose
linker is configured to disregard TLS relocations, this test compiles
and assembles successfully, but execution fails.  The tls_runtime
requirement target avoids the noise from the expected failure.


for  gcc/testsuite/ChangeLog

	* gcc.dg/tls/pr78796.c: Require tls_runtime.

gcc/testsuite/ChangeLog

+2020-04-08  Alexandre Oliva <oliva@adacore.com>
+
+	* gcc.dg/tls/pr78796.c: Require tls_runtime.
+
 2020-04-08  Martin Liska  <mliska@suse.cz>
 
 	PR c++/94314

gcc/testsuite/gcc.dg/tls/pr78796.c

@@ -2,7 +2,7 @@
 /* { dg-do run } */
 /* { dg-options "-O2" } */
 /* { dg-additional-options "-mcmodel=large" { target aarch64-*-* } } */
-/* { dg-require-effective-target tls } */
+/* { dg-require-effective-target tls_runtime } */
 /* { dg-add-options tls } */
 
 struct S { int a, b, c, d, e; };