Fixed GH-19163 fix ext/intl build on midly older compilers but still supporting C++11. (#19353)

Author: devnexen

ext/intl/calendar/gregoriancalendar_methods.cpp

@@ -17,6 +17,7 @@
 #endif
 
 #include "../intl_cppshims.h"
+#include <memory>
 
 #include <unicode/locid.h>
 #include <unicode/calendar.h>

ext/intl/dateformat/dateformat_format_object.cpp

@@ -13,6 +13,7 @@
 */
 
 #include "../intl_cppshims.h"
+#include <memory>
 
 #include <unicode/calendar.h>
 #include <unicode/gregocal.h>

ext/intl/timezone/timezone_class.cpp

@@ -18,6 +18,7 @@
 #endif
 
 #include "../intl_cppshims.h"
+#include <memory>
 
 #include <unicode/timezone.h>
 #include <unicode/calendar.h>