With the VS 2017 tool chain the following errors occur:

jib > t:/workspace/open/src/java.prefs/windows/native/libprefs/WindowsPreferences.c(49): warning C4312: 'type cast': conversion from 'jint' to 'HKEY' of greater size
jib > t:/workspace/open/src/java.prefs/windows/native/libprefs/WindowsPreferences.c(51): warning C4311: 'type cast': pointer truncation from 'HKEY' to 'int'
jib > t:/workspace/open/src/java.prefs/windows/native/libprefs/WindowsPreferences.c(62): warning C4312: 'type cast': conversion from 'jint' to 'HKEY' of greater size
jib > t:/workspace/open/src/java.prefs/windows/native/libprefs/WindowsPreferences.c(75): warning C4312: 'type cast': conversion from 'jint' to 'HKEY' of greater size
jib > t:/workspace/open/src/java.prefs/windows/native/libprefs/WindowsPreferences.c(79): warning C4311: 'type cast': pointer truncation from 'HKEY' to 'int'
jib > t:/workspace/open/src/java.prefs/windows/native/libprefs/WindowsPreferences.c(95): warning C4312: 'type cast': conversion from 'jint' to 'HKEY' of greater size
jib > t:/workspace/open/src/java.prefs/windows/native/libprefs/WindowsPreferences.c(103): warning C4312: 'type cast': conversion from 'jint' to 'HKEY' of greater size
jib > t:/workspace/open/src/java.prefs/windows/native/libprefs/WindowsPreferences.c(115): warning C4312: 'type cast': conversion from 'jint' to 'HKEY' of greater size
jib > t:/workspace/open/src/java.prefs/windows/native/libprefs/WindowsPreferences.c(123): warning C4312: 'type cast': conversion from 'jint' to 'HKEY' of greater size
jib > t:/workspace/open/src/java.prefs/windows/native/libprefs/WindowsPreferences.c(164): warning C4312: 'type cast': conversion from 'jint' to 'HKEY' of greater size
jib > t:/workspace/open/src/java.prefs/windows/native/libprefs/WindowsPreferences.c(179): warning C4312: 'type cast': conversion from 'jint' to 'HKEY' of greater size
jib > t:/workspace/open/src/java.prefs/windows/native/libprefs/WindowsPreferences.c(193): warning C4312: 'type cast': conversion from 'jint' to 'HKEY' of greater size
jib > t:/workspace/open/src/java.prefs/windows/native/libprefs/WindowsPreferences.c(219): warning C4312: 'type cast': conversion from 'jint' to 'HKEY' of greater size
jib > t:/workspace/open/src/java.prefs/windows/native/libprefs/WindowsPreferences.c(243): warning C4312: 'type cast': conversion from 'jint' to 'HKEY' of greater size