copies-rust: fix reverted argument when merging tiny minor or major

The argument where not passed in the right other. This is not caught by the test
(yet) because it is a sub case of a special case. Am I adding this to my list of
things to test. Using test directly in Rust would be appropriate here. However
we don't have the ability to test this code that way yet, and I am focussing on
other part of that work right now.

Differential Revision: https://phab.mercurial-scm.org/D9657

rust/hg-core/src/copy_tracing.rs

@@ -645,7 +645,7 b' fn merge_copies_dict<A: Fn(Revision, Rev'
                 }
                 Some(src_minor) => {
                     let (pick, overwrite) =
-                        cmp_value(oracle, &dest, &src_major, src_minor);
+                        cmp_value(oracle, &dest, src_minor, &src_major);
                     if overwrite {
                         oracle.record_overwrite(src_minor.rev, current_merge);
                         oracle.record_overwrite(src_major.rev, current_merge);
@@ -661,8 +661,8 b' fn merge_copies_dict<A: Fn(Revision, Rev'
                         minor.insert(dest, src);
                     } else {
                         match pick {
-                            MergePick::Any | MergePick::Major => None,
-                            MergePick::Minor => minor.insert(dest, src_major),
+                            MergePick::Any | MergePick::Minor => None,
+                            MergePick::Major => minor.insert(dest, src_major),
                         };
                     }
                 }