Instantiate MseWxHTest and MseHBDWxHTest with C

Instantiate the parameterized tests MseWxHTest and MseHBDWxHTest with C
versions of the aom_mse_wxh_16bit and aom_mse_wxh_16bit_highbd
functions.

This happens to eliminate some strange g++ 10.2.0 warnings on
test/variance_test.cc when libaom is configured with
-DAOM_TARGET_CPU=generic. I don't know why.

BUG=aomedia:2893

Change-Id: I6c78df27504d0dc75465fd0f53bf06c3ab2977d7
diff --git a/test/variance_test.cc b/test/variance_test.cc
index 5bf040c..fa90305 100644
--- a/test/variance_test.cc
+++ b/test/variance_test.cc
@@ -1182,7 +1182,6 @@
 #endif  // !CONFIG_REALTIME_ONLY
 
 typedef MseWxHTestClass<MseWxH16bitFunc> MseWxHTest;
-GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(MseWxHTest);
 typedef MainTestClass<Get4x4SseFunc> AvxSseTest;
 typedef MainTestClass<VarianceMxNFunc> AvxMseTest;
 typedef MainTestClass<VarianceMxNFunc> AvxVarianceTest;
@@ -1219,6 +1218,13 @@
 TEST_P(AvxObmcSubpelVarianceTest, DISABLED_Speed) { SpeedTest(); }
 #endif
 
+INSTANTIATE_TEST_SUITE_P(
+    C, MseWxHTest,
+    ::testing::Values(MseWxHParams(3, 3, &aom_mse_wxh_16bit_c, 8),
+                      MseWxHParams(3, 2, &aom_mse_wxh_16bit_c, 8),
+                      MseWxHParams(2, 3, &aom_mse_wxh_16bit_c, 8),
+                      MseWxHParams(2, 2, &aom_mse_wxh_16bit_c, 8)));
+
 INSTANTIATE_TEST_SUITE_P(C, SumOfSquaresTest,
                          ::testing::Values(aom_get_mb_ss_c));
 
@@ -1506,7 +1512,6 @@
 
 typedef TestParams<MseHBDWxH16bitFunc> MseHBDWxHParams;
 typedef MseHBDWxHTestClass<MseHBDWxH16bitFunc> MseHBDWxHTest;
-GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(MseHBDWxHTest);
 typedef MainTestClass<VarianceMxNFunc> AvxHBDMseTest;
 GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(AvxHBDMseTest);
 typedef MainTestClass<VarianceMxNFunc> AvxHBDVarianceTest;
@@ -1531,6 +1536,13 @@
 TEST_P(AvxHBDSubpelVarianceTest, DISABLED_Speed) { SpeedTest(); }
 TEST_P(AvxHBDSubpelAvgVarianceTest, Ref) { RefTest(); }
 
+INSTANTIATE_TEST_SUITE_P(
+    C, MseHBDWxHTest,
+    ::testing::Values(MseHBDWxHParams(3, 3, &aom_mse_wxh_16bit_highbd_c, 10),
+                      MseHBDWxHParams(3, 2, &aom_mse_wxh_16bit_highbd_c, 10),
+                      MseHBDWxHParams(2, 3, &aom_mse_wxh_16bit_highbd_c, 10),
+                      MseHBDWxHParams(2, 2, &aom_mse_wxh_16bit_highbd_c, 10)));
+
 /* TODO(debargha): This test does not support the highbd version
 INSTANTIATE_TEST_SUITE_P(
     C, AvxHBDMseTest,