sets initial random seed for RANDGEN call
The RANDSEED call creates an initial random seed for subsequent RANDGEN calls. If RANDSEED is not called, an initial seed is generated from the system clock. This call is normally used when it is desirable to reproduce the same random number stream in different IML sessions. The optional reinit parameter controls whether the seed will be reinitialized within the same IML session. If it is set to one, identical seeds will produce the same random number sequence; otherwise a second call
to RANDSEED within the same IML session is ignored. Normally you should not specify reinit, or you should set it to zero to ensure that you are working with an independent random number stream within your IML session.