The following code was necessary when we had HSX, where a JDK can use different versions of libjvm.so, as long as they all support the same JVM_INTERFACE_VERSION.

https://github.com/openjdk/jdk/blob/35c9da70316da21a6be2fd92a5e5b5f193bdd9d6/src/java.base/share/native/libjava/check_version.c#L31

JNIEXPORT jint JNICALL
DEF_JNI_OnLoad(JavaVM *vm, void *reserved)
{
    jint vm_version = JVM_GetInterfaceVersion();
    if (vm_version != JVM_INTERFACE_VERSION) {
        JNIEnv *env;
        char buf[128];
        sprintf(buf, "JVM interface version mismatch: expecting %d, got %d.",
                JVM_INTERFACE_VERSION, (int)vm_version);
        (*vm)->GetEnv(vm, (void **)&env, JNI_VERSION_1_2);
        if (env) {
            (*env)->FatalError(env, buf);
        }
    }
    return JNI_VERSION_1_2;
}

HSX is no longer supported, and we have been modifying the APIs exposed by jvm.h without updating JVM_INTERFACE_VERSION.

JVM_GetInterfaceVersion() and JVM_INTERFACE_VERSION, etc, should be removed.

Also, implementations of APIs such as JVM_DTraceActivate, were removed in JDK-8068976, so their declarations should be removed from jvm.h