Add legacy support for the low-level streaming API

lib/legacy/zstd_v04.c

@@ -4054,3 +4054,11 @@ size_t ZBUFFv04_decompressContinue(ZBUFFv04_DCtx* dctx, void* dst, size_t* maxDs
 {
     return ZBUFF_decompressContinue(dctx, dst, maxDstSizePtr, src, srcSizePtr);
 }
+
+ZSTD_DCtx* ZSTDv04_createDCtx(void) { return ZSTD_createDCtx(); }
+size_t ZSTDv04_freeDCtx(ZSTD_DCtx* dctx) { return ZSTD_freeDCtx(dctx); }
+
+size_t ZSTDv04_getFrameParams(ZSTD_parameters* params, const void* src, size_t srcSize)
+{
+    return ZSTD_getFrameParams(params, src, srcSize);
+}