add regression to the top level and adapt run-tests script

regression/error/Array1.scala

regression/error/Array10.scala

regression/error/Array2.scala

regression/error/Array3.scala

regression/error/Array4.scala

regression/error/Array5.scala

regression/error/Array6.scala

regression/error/Array7.scala

regression/error/Array8.scala

regression/error/Array9.scala

regression/error/InstanceOf1.scala

regression/invalid/Array1.scala

regression/invalid/Array2.scala

regression/invalid/Array3.scala

regression/invalid/Array4.scala

regression/invalid/Array5.scala

regression/invalid/Epsilon1.scala

regression/invalid/Epsilon2.scala

regression/invalid/Epsilon3.scala

regression/invalid/Epsilon4.scala