rust: Remove hex parsing from the nodemap Separating concerns simplifies error types. Differential Revision: https://phab.mercurial-scm.org/D9864

rust: Make NodePrefix allocation-free and Copy, remove NodePrefixRef The `*Ref` struct only existed to avoid allocating `Vec`s when cloning `NodePrefix`, but we can avoid having `Vec` in the first place by using an inline array instead. This makes `NodePrefix` 21 bytes (with 1 for the length) which is smaller than before as `Vec` alone is 24 bytes. Differential Revision: https://phab.mercurial-scm.org/D9863

churn: count lines that look like diff headers but are not Previously, churn cannot count added lines that start with "++ " or removed lines that start with "-- ". Differential Revision: https://phab.mercurial-scm.org/D9929

rust: Exclude empty node prefixes We presumably don’t want `--rev ""` to select every single revision, even though the empty string is a prefix of all strings. Differential Revision: https://phab.mercurial-scm.org/D9862

rust: Simplify error type for reading hex node IDs If a string is not valid hexadecimal it’s not that useful to track the precise reason. Differential Revision: https://phab.mercurial-scm.org/D9861

rust: replace Node::encode_hex with std::fmt::LowerHex This avoids allocating intermediate strings. Differential Revision: https://phab.mercurial-scm.org/D9860

rhg: Build in release mode on CI This follows e73b40c790ec which made tests use the release executable. With e73b40c790ec but not this, tests are skipped on CI because the executable is missing. Differential Revision: https://phab.mercurial-scm.org/D9907