warnings: remove/tweak some dead code

It looks like the dead code detector got better, so do a little code
cleanup.

crates/searcher/src/searcher/core.rs

@@ -467,6 +467,7 @@ impl<'s, M: Matcher, S: Sink> Core<'s, M, S> {
         let keepgoing = self.sink.context(
             &self.searcher,
             &SinkContext {
+                #[cfg(test)]
                 line_term: self.config.line_term,
                 bytes: &buf[*range],
                 kind: SinkContextKind::Before,
@@ -497,6 +498,7 @@ impl<'s, M: Matcher, S: Sink> Core<'s, M, S> {
         let keepgoing = self.sink.context(
             &self.searcher,
             &SinkContext {
+                #[cfg(test)]
                 line_term: self.config.line_term,
                 bytes: &buf[*range],
                 kind: SinkContextKind::After,
@@ -526,6 +528,7 @@ impl<'s, M: Matcher, S: Sink> Core<'s, M, S> {
         let keepgoing = self.sink.context(
             &self.searcher,
             &SinkContext {
+                #[cfg(test)]
                 line_term: self.config.line_term,
                 bytes: &buf[*range],
                 kind: SinkContextKind::Other,

crates/searcher/src/searcher/glue.rs

@@ -88,7 +88,6 @@ where
 
 #[derive(Debug)]
 pub struct SliceByLine<'s, M, S> {
-    config: &'s Config,
     core: Core<'s, M, S>,
     slice: &'s [u8],
 }
@@ -103,7 +102,6 @@ impl<'s, M: Matcher, S: Sink> SliceByLine<'s, M, S> {
         debug_assert!(!searcher.multi_line_with_matcher(&matcher));
 
         SliceByLine {
-            config: &searcher.config,
             core: Core::new(searcher, matcher, write_to, true),
             slice: slice,
         }

crates/searcher/src/sink.rs

@@ -436,6 +436,7 @@ pub enum SinkContextKind {
 /// A type that describes a contextual line reported by a searcher.
 #[derive(Clone, Debug)]
 pub struct SinkContext<'b> {
+    #[cfg(test)]
     pub(crate) line_term: LineTerminator,
     pub(crate) bytes: &'b [u8],
     pub(crate) kind: SinkContextKind,