Multiple CSR Writes for RVVI

Created by: eroom1966

@ross144 Hi Ross, we seem to have an issue with the tracer with respect to CSR updates across the RVVI (imperas branch) The problem we see is that whenever multiple CSR's update for an instruction, only one will update.

The specific case we are looking at is a write to mstatus, which should also update sstatus

a0 <- 0x2000 csrs mstatus, a0

In the code it looks as though only one CSR can be updated for a transaction

The same issue is likely to exist for exceptions where multiple CSR's will be written, eg mcause, mepc, mtval