Add a testcase for PR ld/21529

PR ld/21529
	* testsuite/ld-unique/pr21529.d: New file.
	* testsuite/ld-unique/pr21529.s: Likewise.
	* testsuite/ld-unique/unique.exp: Run *.d.

ld/ChangeLog

@@ -1,3 +1,10 @@
+2017-06-05  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/21529
+	* testsuite/ld-unique/pr21529.d: New file.
+	* testsuite/ld-unique/pr21529.s: Likewise.
+	* testsuite/ld-unique/unique.exp: Run *.d.
+
 2017-06-05  Alan Modra  <amodra@gmail.com>
 
 	* ldmain.c (main): Correct setting of link_indo.new_dtags.

ld/testsuite/ld-unique/pr21529.d

@@ -0,0 +1,8 @@
+#ld: --oformat binary -e main
+#objdump: -s -b binary
+
+.*:     file format binary
+
+Contents of section \.data:
+ 0000 .*
+#pass

ld/testsuite/ld-unique/pr21529.s

@@ -0,0 +1,8 @@
+	.type a, %gnu_unique_object
+a:	.long 0
+	.size a, .-a
+
+        .type main,"function"
+        .global main
+main:
+        .dc.a a

ld/testsuite/ld-unique/unique.exp

@@ -35,7 +35,12 @@ if { ![supports_gnu_unique] } {
     return
 }
 
-run_dump_test "unique"
+set test_list [lsort [glob -nocomplain $srcdir/$subdir/*.d]]
+foreach t $test_list {
+    # We need to strip the ".d", but can leave the dirname.
+    verbose [file rootname $t]
+    run_dump_test [file rootname $t]
+}
 
 # We need a working compiler.  (Strictly speaking this is
 # not true, we could use target specific assembler files).