Unable to set the PBMTE bit in the menvcfg register for RISCV 64 bit
Description of problem:
We are unable to program the PBMTE bit in the menvcfg register of a RV64 machine. The following is the command that was used to do this.
 
write_csr(menvcfg,PTE_PBMT);
Steps to reproduce:
1. A simple test program with the above command should be able to reproduce this issue.