Make roken build on windows

Signed-off-by: Love Hornquist Astrand <lha@h5l.org>

lib/roken/strpftime-test.h

@@ -45,4 +45,11 @@
 #define strftime test_strftime
 #define strptime test_strptime
 
+ROKEN_LIB_FUNCTION size_t ROKEN_LIB_CALL
+strftime (char *buf, size_t maxsize, const char *format,
+          const struct tm *tm);
+
+ROKEN_LIB_FUNCTION char * ROKEN_LIB_CALL
+strptime (const char *buf, const char *format, struct tm *timeptr);
+
 #endif /* __STRFTIME_TEST_H__ */