`CHECK_F` macro moved to `error_private.h` (shared between `fse_compress.c` and `fse_decompress.c`). `ZSTD_limitCopy()` moved to `zstd_internal.h` (shared between `zstd_compress.c` and `zstd_decompress.c`). Erroneous build artefact `zstd.h` removed from repo.