build: resolve build failure on freebsd/clang

include/gromox/mapidefs.h:925:17: error: unknown type name 'time_t'
  925 |         freebusy_event(time_t, time_t, uint32_t, const char *, const char *, const char *, bool, bool, bool, bool, bool, bool);
tests/utf8filter.cpp:11:57: error: use of undeclared identifier 'STDIN_FILENO'
   11 |         std::unique_ptr<char[], stdlib_delete> buf(HX_slurp_fd(STDIN_FILENO, &size));
exch/exmdb/db_engine.cpp:573:55: error: use of undeclared identifier 'S_IXUSR'
  573 |         int ret = gx_mkbasedir(path.c_str(), FMODE_PRIVATE | S_IXUSR | S_IXGRP);
tools/eml2mbox.cpp:18:13: error: use of undeclared identifier 'time'
   18 |         auto now = time(nullptr);

Author: jengelh

exch/exmdb/db_engine.cpp

@@ -27,6 +27,7 @@
 #include <utility>
 #include <vector>
 #include <fmt/core.h>
+#include <sys/stat.h>
 #include <libHX/scope.hpp>
 #include <gromox/atomic.hpp>
 #include <gromox/clock.hpp>

include/gromox/mapidefs.h

@@ -3,6 +3,7 @@
 #include <compare>
 #include <cstdint>
 #include <cstring>
+#include <ctime>
 #include <memory>
 #include <optional>
 #include <string>

tests/utf8filter.cpp

@@ -1,6 +1,10 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// SPDX-FileCopyrightText: 2025 grommunio GmbH
+// This file is part of Gromox.
 #include <cstdlib>
 #include <cstring>
 #include <memory>
+#include <unistd.h>
 #include <libHX/io.h>
 #include <gromox/defs.h>
 #include <gromox/util.hpp>

tools/eml2mbox.cpp

@@ -5,6 +5,7 @@
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
+#include <ctime>
 #include <memory>
 #include <libHX/io.h>
 #include <libHX/scope.hpp>