Adding missing files

src/main/scala/leon/invariant/engine/InferenceReport.scala

src/main/scala/leon/transformations/InstProgSimplifier.scala

...main/scala/leon/transformations/InstrumentationUtil.scala

src/main/scala/leon/transformations/IntToRealProgram.scala

...a/leon/transformations/NonlinearityEliminationPhase.scala

...ala/leon/transformations/SerialInstrumentationPhase.scala

src/test/scala/leon/regression/orb/OrbRegressionSuite.scala