In parsing, when the callsub is the last instruction of the program, the called subroutine is not identified as a "Subroutine" by Tealer.
In TransactionFieldAnalysis, when a subroutine uses the return opcode instead of retsub. Analysis results in incorrect information about possible values for the transaction fields. This in turn affects the detector results
This PR addresses two bugs
callsubis the last instruction of the program, the called subroutine is not identified as a "Subroutine" by Tealer.returnopcode instead ofretsub. Analysis results in incorrect information about possible values for the transaction fields. This in turn affects the detector results