fix and implement ConditionalBranchFolder, Unreachable Code Eliminator

[sahilagichani14]

Todo: fix for try-catch blocks

[swissiety]

this seems expensive - old Soot did cut the connection to the never reached branch and was calling UnreachableCodeEliminator afterwards, which at least looks simpler/cleaner than the current state (havent checked if the proposed algorithm is faster e.g. due to a possible smaller n?)

[sahilagichani14]

this seems expensive - old Soot did cut the connection to the never reached branch and was calling UnreachableCodeEliminator afterwards, which at least looks simpler/cleaner than the current state (havent checked if the proposed algorithm is faster e.g. due to a possible smaller n?)

Old soot has a connection to statements and not blocks, so removing a statement is simpler than removing intermediate blocks.

[swissiety]

this seems expensive - old Soot did cut the connection to the never reached branch and was calling UnreachableCodeEliminator afterwards, which at least looks simpler/cleaner than the current state (havent checked if the proposed algorithm is faster e.g. due to a possible smaller n?)

Old soot has a connection to statements and not blocks, so removing a statement is simpler than removing intermediate blocks.

can you explain why? I would assume it is instantly "infecting" the complete block (so all its following FallsthroughStmts) if that (head)stmt needs to be removed and not just unlinked from the IfStmt. So it would skip the checks on the "infected" block and only has to go on with the checks on the next block instead of each Stmt of the infected Block. -- Lets have a call.

[swissiety]

fixing the iterator should have fixed:

• [Bug]: A runtime crash when analyzing Lucence library #953
  as well.

[sahilagichani14]

#996