Use unstable instead of stable sorts

src/function.rs

@@ -158,7 +158,7 @@ impl<R: gimli::Reader> Functions<R> {
         // It's possible for multiple functions to have the same address range if the
         // compiler can detect and remove functions with identical code.  In that case
         // we'll nondeterministically return one of them.
-        addresses.sort_by_key(|x| x.range.begin);
+        addresses.sort_unstable_by_key(|x| x.range.begin);
 
         Ok(Functions {
             functions: functions.into_boxed_slice(),
@@ -252,7 +252,7 @@ impl<R: gimli::Reader> Function<R> {
         // In this example, if you want to look up address 7 at depth 0, and you
         // encounter [0..2 at depth 1], are you before or after the target range?
         // You don't know.
-        state.addresses.sort_by(|r1, r2| {
+        state.addresses.sort_unstable_by(|r1, r2| {
             if r1.call_depth < r2.call_depth {
                 Ordering::Less
             } else if r1.call_depth > r2.call_depth {

src/line.rs

@@ -94,7 +94,7 @@ impl Lines {
                 column,
             });
         }
-        sequences.sort_by_key(|x| x.start);
+        sequences.sort_unstable_by_key(|x| x.start);
 
         let mut files = Vec::new();
         let header = rows.header();

src/unit.rs

@@ -208,7 +208,7 @@ impl<R: gimli::Reader> ResUnits<R> {
         while let Some(header) = headers.next()? {
             aranges.push((header.debug_info_offset(), header.offset()));
         }
-        aranges.sort_by_key(|i| i.0);
+        aranges.sort_unstable_by_key(|i| i.0);
 
         let mut unit_ranges = Vec::new();
         let mut res_units = Vec::new();
@@ -362,7 +362,7 @@ impl<R: gimli::Reader> ResUnits<R> {
         }
 
         // Sort this for faster lookup in `Self::find_range`.
-        unit_ranges.sort_by_key(|i| i.range.end);
+        unit_ranges.sort_unstable_by_key(|i| (i.range.end, i.unit_id));
 
         // Calculate the `min_begin` field now that we've determined the order of
         // CUs.