Update recent Issue 541 due to differences in RISC-V vs. IEEE 754 for fp -> integer/long conversion

Created by: stineje

Make changes to interpret config.vh for fp -> int (e.g., f128_to_ui32 and f128_to_i32) for IEEE 754 vs. RISC-V (i.e., Table 11.4: Domains of float-to-integer conversions and behavior for invalid inputs. in RISC-V Unprivileged ISA manual).