The specific (3) warnings, as at time of writing.

jdk/src/java.security.jgss/share/classes/sun/security/krb5/internal/crypto/Des.java:275: warning: [lossy-conversions] implicit cast from int to byte in compound assignment is possibly lossy
            temp[7] ^= 0xf0;
                       ^
jdk/src/java.security.jgss/share/classes/sun/security/krb5/internal/crypto/Des.java:283: warning: [lossy-conversions] implicit cast from int to byte in compound assignment is possibly lossy
            temp[7] ^= 0xf0;
                       ^
jdk/src/java.security.jgss/share/classes/sun/security/krb5/internal/crypto/dk/Des3DkCrypto.java:160: warning: [lossy-conversions] implicit cast from int to byte in compound assignment is possibly lossy
                last |= (bit<<posn);
                        ^