Gradle ant task multiple/concatenated classpath

Translating this into gradle would be something like

configurations {
   hibernateTool
} 
dependencies {
   hibernateTool fileTree('WebContent/WEB-INF/lib') {
      include '*.jar'
   } 
   hibernateTool sourceSets.main.runtimeClasspath 
} 
task myTask {
   doLast {
      ant.taskdef(name:'hibernatetool', classname: 'org.hibernate.tool.ant.HibernateToolTask', classpath: configurations.hibernateTool.asPath)
      ant.hibernatetool(...)
   } 
}