riscv64 SCS support.

Bug: https://github.com/google/android-riscv64/issues/55
Test: treehugger
Change-Id: I05d48a07a302305126942d38529ffa280640c7b7
diff --git a/tests/scs_test.cpp b/tests/scs_test.cpp
index 24cb347..0776a43 100644
--- a/tests/scs_test.cpp
+++ b/tests/scs_test.cpp
@@ -14,8 +14,6 @@
  * limitations under the License.
  */
 
-#if __has_feature(shadow_call_stack)
-
 #include <gtest/gtest.h>
 
 #include "private/bionic_constants.h"
@@ -33,7 +31,9 @@
 }
 
 TEST(scs_test, stack_overflow) {
+#if defined(__aarch64__) || defined(__riscv)
   ASSERT_EXIT(recurse1(SCS_SIZE), testing::KilledBySignal(SIGSEGV), "");
-}
-
+#else
+  GTEST_SKIP() << "no SCS on this architecture";
 #endif
+}