Negative parameter indexes

A recent addition to the CV32E40X (sha 4206fff4 on 2021-04-27) introduced "negative indexes" for the PMA_CFG parameter. An example of this is bhv/cv32e40x_wrapper.sv:

module cv32e40x_wrapper
  import cv32e40x_pkg::*;
#(
  parameter NUM_MHPMCOUNTERS             =  1,
  parameter int unsigned PMA_NUM_REGIONS =  0,
  parameter pma_region_t PMA_CFG [PMA_NUM_REGIONS-1:0] = '{default:PMA_R_DEFAULT}
)

The default value of PMA_NUM_REGIONS is zero which means the range of PMA_CFG is [-1:0]. Most SV simulators will accept this, but Metrics DSIM interprets SV parameters as unsigned values (which, I believe is correct) and therefore the size of PMA_CFG is (2**31)-1 which exceeds a built-in DSIM limit.