permission-set - type:OBJECT
Expected (target server default):
{
    "login-permission" : {"permissions" : [{"class-name" : "org.wildfly.security.auth.permission.LoginPermission"}]},
    "default-permissions" : {"permissions" : [
        {
            "class-name" : "org.wildfly.extension.batch.jberet.deployment.BatchPermission",
            "module" : "org.wildfly.extension.batch.jberet",
            "target-name" : "*"
        },
        {
            "class-name" : "org.wildfly.transaction.client.RemoteTransactionPermission",
            "module" : "org.wildfly.transaction.client"
        },
        {
            "class-name" : "org.jboss.ejb.client.RemoteEJBPermission",
            "module" : "org.jboss.ejb-client"
        }
    ]}
}

Actual (created by migration tool):
null
===============================
simple-permission-mapper - type:OBJECT
Expected (target server default):
{"default-permission-mapper" : {
    "mapping-mode" : "first",
    "permission-mappings" : [
        {
            "principals" : ["anonymous"],
            "permission-sets" : [{"permission-set" : "default-permissions"}]
        },
        {
            "match-all" : true,
            "permission-sets" : [
                {"permission-set" : "login-permission"},
                {"permission-set" : "default-permissions"}
            ]
        }
    ]
}}

Actual (created by migration tool):
{"default-permission-mapper" : {
    "mapping-mode" : "first",
    "permission-mappings" : [
        {
            "principals" : ["anonymous"],
            "permissions" : [
                {
                    "class-name" : "org.wildfly.extension.batch.jberet.deployment.BatchPermission",
                    "module" : "org.wildfly.extension.batch.jberet",
                    "target-name" : "*"
                },
                {
                    "class-name" : "org.wildfly.transaction.client.RemoteTransactionPermission",
                    "module" : "org.wildfly.transaction.client"
                },
                {
                    "class-name" : "org.jboss.ejb.client.RemoteEJBPermission",
                    "module" : "org.jboss.ejb-client"
                }
            ]
        },
        {
            "match-all" : true,
            "permissions" : [
                {"class-name" : "org.wildfly.security.auth.permission.LoginPermission"},
                {
                    "class-name" : "org.wildfly.extension.batch.jberet.deployment.BatchPermission",
                    "module" : "org.wildfly.extension.batch.jberet",
                    "target-name" : "*"
                },
                {
                    "class-name" : "org.wildfly.transaction.client.RemoteTransactionPermission",
                    "module" : "org.wildfly.transaction.client"
                },
                {
                    "class-name" : "org.jboss.ejb.client.RemoteEJBPermission",
                    "module" : "org.jboss.ejb-client"
                }
            ]
        }
    ]
}}