Keep ZSTD_endStream's streaming call, error propagation, multithreaded
minimal estimate, logging, and context state in C. Move only the final
single-thread estimate behind a scalar Rust ABI helper so the frame-ended
branch and raw checksum flag are explicit while size_t arithmetic wraps as
in C.
Test Plan:
- `cargo clippy --manifest-path rust/Cargo.toml --no-default-features --features compression` -- passed before and after formatting.
- The same clippy command with `--benches` and `--tests` -- passed before and after formatting.
- `cargo +nightly fmt --manifest-path rust/Cargo.toml` -- passed.
- Focused end-stream Rust tests -- 4 passed.
- `make -B -C lib -j2 lib` -- passed.
- `make -C tests test-rust-lib-smoke` -- passed.
- `tests/fuzzer -s4560 -t56 -i57 -v` -- passed.
- `make -C tests -j2 test-zstream` -- passed: 84 named, 6,457, and 8,692 randomized tests. The pre-existing unterminated-string warning remains.
- `git diff --check` and `git diff --cached --check` -- passed.
ddidderr
fcec7d3cc6