Make IWYU output in lint.cpp less messy

And re-run IWYU, adjust #includes.

src/autoload.cpp

@@ -4,13 +4,13 @@
 #include <assert.h>
 #include <errno.h>
 #include <pthread.h>
-#include <stdbool.h>
 #include <stddef.h>
 #include <sys/stat.h>
 #include <time.h>
 #include <unistd.h>
 #include <wchar.h>
 #include <algorithm>
+#include <memory>
 #include <set>
 #include <string>
 #include <utility>