The specific (5) warnings, as of time of writing.

jdk/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/ui/classbrowser/HTMLGenerator.java:952: warning: [lossy-conversions] implicit cast from long to int in compound assignment is possibly lossy
         instrSize += endPc - pc;
                            ^
jdk/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/utilities/HeapHprofBinWriter.java:540: warning: [lossy-conversions] implicit cast from long to int in compound assignment is possibly lossy
            size += OBJ_ID_SIZE * 5 + INT_SIZE + SHORT_SIZE;
                                               ^
jdk/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/utilities/HeapHprofBinWriter.java:554: warning: [lossy-conversions] implicit cast from long to int in compound assignment is possibly lossy
            size += OBJ_ID_SIZE * 5 + INT_SIZE + SHORT_SIZE * 3;
                                                ^
jdk/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/utilities/HeapHprofBinWriter.java:561: warning: [lossy-conversions] implicit cast from long to int in compound assignment is possibly lossy
        size += SHORT_SIZE;
                ^
jdk/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/utilities/HeapHprofBinWriter.java:563: warning: [lossy-conversions] implicit cast from long to int in compound assignment is possibly lossy
            size += OBJ_ID_SIZE + BYTE_SIZE;
                                ^