We are planning to have Graal as experimental JIT compiler in next release.
For that we should enable its build regardless AOT build which is current condition:

    # By default enable graal build where AOT is available
    if test "x$ENABLE_AOT" = "xtrue"; then
      AC_MSG_RESULT([yes])
      JVM_FEATURES_graal="graal"
      INCLUDE_GRAAL="true"