Unify Guarded and Simple case

src/main/scala/leon/evaluators/RecursiveEvaluator.scala

src/main/scala/leon/frontends/scalac/CodeExtraction.scala

src/main/scala/leon/purescala/Constructors.scala

src/main/scala/leon/purescala/Extractors.scala

src/main/scala/leon/purescala/FunctionClosure.scala

src/main/scala/leon/purescala/PrettyPrinter.scala

src/main/scala/leon/purescala/ScopeSimplifier.scala

src/main/scala/leon/purescala/TransformerWithPC.scala

src/main/scala/leon/purescala/TreeOps.scala

src/main/scala/leon/purescala/Trees.scala

src/main/scala/leon/refactor/Repairman.scala

src/main/scala/leon/synthesis/rules/GuidedDecomp.scala

src/main/scala/leon/termination/StructuralSize.scala

src/main/scala/leon/utils/UnitElimination.scala

src/main/scala/leon/xlang/ArrayTransformation.scala

src/main/scala/leon/xlang/ImperativeCodeElimination.scala