S/390: Fix larl/PIC test case.

This patch adds -march=z900 to a test case that expects larl for loading
a value via the GOT.  On z10 and later, lgrl is used which is tested in
a new, separate test case.

gcc/testsuite/ChangeLog:

2019-05-17  Robin Dapp  <rdapp@linux.ibm.com>

  * gcc.target/s390/global-array-element-pic.c: Add -march=z900.
  * gcc.target/s390/global-array-element-pic2.c: New test for z10+.

From-SVN: r271321

gcc/testsuite/ChangeLog

+2019-05-17  Robin Dapp  <rdapp@linux.ibm.com>
+
+	* gcc.target/s390/global-array-element-pic.c: Add -march=z900.
+	* gcc.target/s390/global-array-element-pic2.c: New test for z10+.
+
 2019-05-17  Richard Biener  <rguenther@suse.de>
 
 	* gcc.dg/gimplefe-41.c: New testcase.

gcc/testsuite/gcc.target/s390/global-array-element-pic.c

 /* Test accesses to global array elements in PIC code.  */
 /* { dg-do compile } */
-/* { dg-options "-O1 -fPIC" } */
+/* { dg-options "-O1 -march=z900 -fPIC" } */
 
 extern char a[] __attribute__ ((aligned (2)));
 extern char *b;

gcc/testsuite/gcc.target/s390/global-array-element-pic2.c

+/* Test accesses to global array elements in PIC code.  */
+/* { dg-do compile } */
+/* { dg-options "-O1 -march=z10 -fPIC" } */
+
+extern char a[] __attribute__ ((aligned (2)));
+extern char *b;
+
+void c()
+{
+  b = a + 4;
+  /* { dg-final { scan-assembler {(?n)\n\tlgrl\t%r\d+,a@GOTENT\n} } } */
+  /* { dg-final { scan-assembler-not {(?n)\n\tlarl\t%r\d+,a[^@]} } } */
+}