chore: add vendor dependencies for kauma build

vendor/memchr/src/tests/substring/naive.rs

@@ -0,0 +1,45 @@
+/*!
+This module defines "naive" implementations of substring search.
+
+These are sometimes useful to compare with "real" substring implementations.
+The idea is that they are so simple that they are unlikely to be incorrect.
+*/
+
+/// Naively search forwards for the given needle in the given haystack.
+pub(crate) fn find(haystack: &[u8], needle: &[u8]) -> Option<usize> {
+    let end = haystack.len().checked_sub(needle.len()).map_or(0, |i| i + 1);
+    for i in 0..end {
+        if needle == &haystack[i..i + needle.len()] {
+            return Some(i);
+        }
+    }
+    None
+}
+
+/// Naively search in reverse for the given needle in the given haystack.
+pub(crate) fn rfind(haystack: &[u8], needle: &[u8]) -> Option<usize> {
+    let end = haystack.len().checked_sub(needle.len()).map_or(0, |i| i + 1);
+    for i in (0..end).rev() {
+        if needle == &haystack[i..i + needle.len()] {
+            return Some(i);
+        }
+    }
+    None
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::tests::substring;
+
+    use super::*;
+
+    #[test]
+    fn forward() {
+        substring::Runner::new().fwd(|h, n| Some(find(h, n))).run()
+    }
+
+    #[test]
+    fn reverse() {
+        substring::Runner::new().rev(|h, n| Some(rfind(h, n))).run()
+    }
+}