Turn on unit test for inverse 16x16 2D-DCT ssse3

Change-Id: I02250d1364ca2e637585a8db020cba9fd4a95664

test/dct16x16_test.cc

diff --git a/test/dct16x16_test.cc b/test/dct16x16_test.cc
index 7900bcf..b396a51 100644
--- a/test/dct16x16_test.cc
+++ b/test/dct16x16_test.cc
@@ -536,4 +536,11 @@
         make_tuple(&vp9_fht16x16_sse2, &vp9_iht16x16_256_add_sse2, 2),
         make_tuple(&vp9_fht16x16_sse2, &vp9_iht16x16_256_add_sse2, 3)));
 #endif
+
+#if HAVE_SSSE3
+INSTANTIATE_TEST_CASE_P(
+    SSSE3, Trans16x16DCT,
+    ::testing::Values(
+        make_tuple(&vp9_fdct16x16_c, &vp9_idct16x16_256_add_ssse3, 0)));
+#endif
 }  // namespace