Remove ValDef.isLazy, treat byName argument during extraction alone

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

...scala/leon/invariant/engine/UnfoldingTemplateSolver.scala

src/main/scala/leon/invariant/util/TreeUtil.scala

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

src/main/scala/leon/purescala/Definitions.scala

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

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

src/main/scala/leon/synthesis/ExamplesFinder.scala

...n/scala/leon/synthesis/disambiguation/ExamplesAdder.scala

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

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