New regression test from Mark's fuzzing test cases

Makefile.am

@@ -102,7 +102,7 @@ opus_compare_LDADD = $(LIBM)
 tests_test_opus_api_SOURCES = tests/test_opus_api.c tests/test_opus_common.h
 tests_test_opus_api_LDADD = libopus.la $(NE10_LIBS) $(LIBM)
 
-tests_test_opus_encode_SOURCES = tests/test_opus_encode.c tests/test_opus_common.h
+tests_test_opus_encode_SOURCES = tests/test_opus_encode.c tests/opus_encode_regressions.c tests/test_opus_common.h
 tests_test_opus_encode_LDADD = libopus.la $(NE10_LIBS) $(LIBM)
 
 tests_test_opus_decode_SOURCES = tests/test_opus_decode.c tests/test_opus_common.h

tests/test_opus_common.h

@@ -76,3 +76,5 @@ static OPUS_INLINE void _test_failed(const char *file, int line)
   abort();
 }
 #define test_failed() _test_failed(__FILE__, __LINE__);
+
+void regression_test(void);

tests/test_opus_encode.c

@@ -680,6 +680,8 @@ int main(int _argc, char **_argv)
    fprintf(stderr,"Testing %s encoder. Random seed: %u (%.4X)\n", oversion, iseed, fast_rand() % 65535);
    if(env_used)fprintf(stderr,"  Random seed set from the environment (SEED=%s).\n", env_seed);
 
+   regression_test();
+
    /*Setting TEST_OPUS_NOFUZZ tells the tool not to send garbage data
      into the decoders. This is helpful because garbage data
      may cause the decoders to clip, which angers CLANG IOC.*/