Riscv-isac

- Add support to decode compressed instructions

- Improve data propagation reports to capture multiple signature updates per coverpoint
- Add a CLI flag to explicitly log the redundant coverpoints while normalizing the CGF files

- Fix length of commitval to 32 bits if flen is 32 for f registers in sail parser.

- Refactored the instruction object class

- Added support for instruction aliases

- Add fields to instruction object
- Enable generic coverage evaluation mechanisms for floating point instructions
- Fix coverpoint generation to account for nan boxing of fp instructions.
- Add fields(frm, fcsr, nan_prefix) for fp instructions