Added a 'first_op' to track the first operation of multi operation in…

Created by: silabs-oysteink

…structions through the pipeline.

RVFI will now only latch rs1/2_rdata when the first operation of a multi operation instruction is in the ID stage.

Added assertions to check that jump targets are stable when remaining in ID for multiple cycles. Added assertion to check that RVFI may use operand_a_fw also for JALR instructions, although JALR uses a different bypass mux in RTL.

SEC clean.

Signed-off-by: Oystein Knauserud Oystein.Knauserud@silabs.com