sync: attempt to auto-resolve non-libbpf conflicts

If cherry-picked commit contains non-libbpf files, chances are high that
this will result in conflict, because we are generally skipping commits
that didn't touch libbpf files, which means that our working copy will
not be up-to-date for non-libbpf files. This change checks if conflicts
are only in non-libbpf files and marks them as resolved. This will work
fine as long as we don't cherry-pick some more non-libbpf changes to
same set of files that happen to conflict with not-so-resolved version
of non-libbpf files. But anyways, this should help in a lot of cases.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>

scripts/sync-kernel.sh

@@ -104,6 +104,7 @@ cherry_pick_commits()
 	local should_skip
 	local synced_cnt
 	local manual_check
+	local libbpf_conflict_cnt
 	local desc
 
 	new_commits=$(git rev-list --no-merges --topo-order --reverse ${baseline_tag}..${tip_tag} ${LIBBPF_PATHS[@]})
@@ -139,6 +140,21 @@ cherry_pick_commits()
 		# commit hasn't been synced into libbpf yet
 		echo "Picking '${desc}'..."
 		if ! git cherry-pick ${new_commit} &>/dev/null; then
+			echo "Warning! Cherry-picking '${desc} failed, checking if it's non-libbpf files causing problems..."
+			libbpf_conflict_cnt=$(git diff --name-only --diff-filter=U -- ${LIBBPF_PATHS[@]} | wc -l)
+
+			if ((${libbpf_conflict_cnt} == 0)); then
+				echo "Looks like only non-libbpf files have conflicts, ignoring..."
+				git add .
+				# GIT_EDITOR=true to avoid editor popping up to edit commit message
+				if ! GIT_EDITOR=true git cherry-pick --continue; then
+					echo "Error! That still failed! Please resolve manually."
+				else
+					echo "Success! All cherry-pick conflicts were resolved for '${desc}'!"
+					continue
+				fi
+			fi
+
 			read -p "Error! Cherry-picking '${desc}' failed, please fix manually and press <return> to proceed..."
 		fi
 	done