fcvt.h.l fixes, removed delays

Created by: davidharrishmc

Need to cd into addins/riscv-arch-test and pull to incorporate the corrected Zfh tests

This PR adds a covergen program to start directed functional coverage generation. cd $WALLY/tests/testgen ./covergen.py Look at tests/wally-riscv-arch-test/rv64i_m/..../WALLY-COV-*.S tests and make sure they look good cd $WALLY/sim make wally-riscv-arch-test iter-elf.bash --search ../tests/riscof/work/wally-riscv-arch-test/rv64i_m/I/src/WALLY-COV-XOR.S/ref --cover (to run one test) iter-elf.bash --search ../tests/riscof/work/wally-riscv-arch-test/rv64i_m/I/src (to run all tests) Look at riscv.ucdb.log to see coverage (e.g. under xor)

At 91% xor test coverage right now. Haven't written cp_rd_maxvals (maybe do by hand based on instruction type?) cmp_rd_rs1_rs2 isn't working right - I must not understand it correctly yet. cp_gpr_hazard isn't covering WAR hazards yet - I must not understand those either.