MSVC: compat: implement realpath()
diff --git a/CMakeModules/UseCompat.cmake b/CMakeModules/UseCompat.cmake
index f9d98a0..31bd59f 100644
--- a/CMakeModules/UseCompat.cmake
+++ b/CMakeModules/UseCompat.cmake
@@ -51,6 +51,8 @@
     check_struct_has_member("struct tm" tm_gmtoff time.h HAVE_TM_GMTOFF)
     check_symbol_exists(timezone time.h HAVE_TIME_H_TIMEZONE)
 
+    check_symbol_exists(realpath "stdlib.h" HAVE_REALPATH)
+
     unset(CMAKE_REQUIRED_DEFINITIONS)
     unset(CMAKE_REQUIRED_LIBRARIES)