Issues with Duplicated Labels

[ThomasHaas]

Code that contains multiple labels with the same name causes various problems:

• The parsing generates bogus code if the same label name is used in different threads. This should not be a problem in principle.
• If the same thread contains duplicate labels, the parser generates programs with cyclic getSuccessor-relation and runs into an infinite loop trying to find the exit event.

The underlying issues are

• The ProgramBuilder tracks labels globally instead of per thread (causing issue 1).
• The method getOrCreateLabel is used throughout. This causes creation of labels in cases where none should get created and retrieval of existing labels when new ones should get created.