Skip gcc.target/aarch64/sve/tls_preserve* for emultls targets

These tests are supposed to be testing the tlsdesc handling and
so don't apply to emultls targets.

2020-01-22  Richard Sandiford  <richard.sandiford@arm.com>

gcc/testsuite/
	* gcc.target/aarch64/sve/tls_preserve_1.c: Require tls_native.
	* gcc.target/aarch64/sve/tls_preserve_2.c: Likewise.
	* gcc.target/aarch64/sve/tls_preserve_3.c: Likewise.

gcc/testsuite/ChangeLog

 2020-01-22  Richard Sandiford  <richard.sandiford@arm.com>
 
+	* gcc.target/aarch64/sve/tls_preserve_1.c: Require tls_native.
+	* gcc.target/aarch64/sve/tls_preserve_2.c: Likewise.
+	* gcc.target/aarch64/sve/tls_preserve_3.c: Likewise.
+
+2020-01-22  Richard Sandiford  <richard.sandiford@arm.com>
+
 	* gcc.target/aarch64/sve/sel_3.c (permute_vnx4sf): Take __SVFloat32_t
 	rather than __SVFloat16_t
 

gcc/testsuite/gcc.target/aarch64/sve/tls_preserve_1.c

 /* { dg-do compile } */
 /* { dg-options "-O3 -fpic" } */
 /* { dg-require-effective-target fpic } */
-
-/* Clobber highs do not need to be spilled around tls usage.  */
+/* { dg-require-effective-target tls_native } */
 
 typedef float v4si __attribute__ ((vector_size (16)));
 

gcc/testsuite/gcc.target/aarch64/sve/tls_preserve_2.c

 /* { dg-do compile } */
 /* { dg-options "-O3 -fpic -msve-vector-bits=256 -fno-schedule-insns" } */
 /* { dg-require-effective-target fpic } */
-
-/* Clobber highs must be spilled around tls usage.  */
+/* { dg-require-effective-target tls_native } */
 
 typedef float v8si __attribute__ ((vector_size (32)));
 

gcc/testsuite/gcc.target/aarch64/sve/tls_preserve_3.c

 /* { dg-do compile } */
 /* { dg-options "-O3 -fpic -msve-vector-bits=512 -fno-schedule-insns" } */
 /* { dg-require-effective-target fpic } */
-
-/* Clobber highs must be spilled around tls usage.  */
+/* { dg-require-effective-target tls_native } */
 
 typedef float v16si __attribute__ ((vector_size (64)));