Abort if Unsupported Parameters Used

lib/compress/zstd_ldm.c

@@ -248,6 +248,8 @@ static size_t ZSTD_ldm_fillFastTables(ZSTD_matchState_t* ms,
     case ZSTD_dfast:
 #ifndef ZSTD_EXCLUDE_DFAST_BLOCK_COMPRESSOR
         ZSTD_fillDoubleHashTable(ms, iend, ZSTD_dtlm_fast, ZSTD_tfp_forCCtx);
+#else
+        assert(0); /* shouldn't be called: cparams should've been adjusted. */
 #endif
         break;