[nix] run vcs simv with "-exitstataus"

with "-exitstatus" simv will return non-zero exit code when $error/$fatal or assertion failed

nix/t1/run/run-vcs-emu.nix

@@ -13,6 +13,7 @@ stdenvNoCC.mkDerivation (finalAttr: {
     mkdir -p "$out"
 
     emuDriverArgsArray=(
+      "-exitstatus"
       "+t1_elf_file=${testCase}/bin/${testCase.pname}.elf"
       ${lib.optionalString emulator.enableTrace "+t1_wave_path=${testCase.pname}.fsdb"}
       "-cm assert"