Enable windows build, set mac builds for gitlab runners

multiplatform-crypto-libsodium-bindings/src/nativeMain/kotlin/com/ionspin/kotlin/crypto/util/LibsodiumUtil.kt

@@ -12,6 +12,7 @@ import libsodium.sodium_memcmp
 import libsodium.sodium_memzero
 import libsodium.sodium_pad
 import libsodium.sodium_unpad
+import platform.posix.size_tVar
 
 /**
  * Created by Ugljesa Jovanovic