[iwyu] include cleanup

src/db_sub_source.cc

@@ -27,8 +27,6 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <regex>
-
 #include "db_sub_source.hh"
 
 #include "base/date_time_scanner.hh"

src/pretty_printer.cc

@@ -29,6 +29,10 @@
 
 #include "pretty_printer.hh"
 
+#include <sys/types.h>
+
+#include "base/auto_mem.hh"
+#include "base/intern_string.hh"
 #include "base/string_util.hh"
 #include "config.h"
 

src/pretty_printer.hh

@@ -31,19 +31,16 @@
 #define pretty_printer_hh
 
 #include <deque>
-#include <map>
 #include <sstream>
 #include <stack>
-#include <utility>
+#include <string>
 #include <vector>
 
-#include <sys/types.h>
-
 #include "base/attr_line.hh"
 #include "base/file_range.hh"
-#include "base/opt_util.hh"
 #include "data_scanner.hh"
 #include "document.sections.hh"
+#include "optional.hpp"
 
 class pretty_printer {
 public: