Optimized the TypeRestrictor.

src/main/java/de/b2tla/B2TlaTranslator.java

...main/java/de/b2tla/analysis/ConstantExpressionFinder.java

src/main/java/de/b2tla/analysis/ConstantsEvaluator.java

src/main/java/de/b2tla/analysis/IdentifierDependencies.java

src/main/java/de/b2tla/analysis/PrecedenceCollector.java

src/main/java/de/b2tla/analysis/TypeRestrictor.java

src/main/java/de/b2tla/analysis/Typechecker.java

src/main/java/de/b2tla/btypes/BType.java

src/main/java/de/b2tla/btypes/BoolType.java

src/main/java/de/b2tla/btypes/FunctionType.java

src/main/java/de/b2tla/btypes/IntegerOrSetOfPairType.java

src/main/java/de/b2tla/btypes/IntegerOrSetType.java

src/main/java/de/b2tla/btypes/IntegerType.java

src/main/java/de/b2tla/btypes/ModelValueType.java

src/main/java/de/b2tla/btypes/PairType.java

src/main/java/de/b2tla/btypes/SetType.java

src/main/java/de/b2tla/btypes/StringType.java

src/main/java/de/b2tla/btypes/StructType.java

src/main/java/de/b2tla/btypes/UntypedType.java

src/main/java/de/b2tla/prettyprint/TLAPrinter.java