Performance significantly worse than dash

I don't know if this is a real issue or just because the project isn't really mature yet, but because afaik there is no irc server where I could talk about this, I wanted to create this issue:
When comparing the run times of this test code in mrsh and in dash:
```sh
#!/bin/sh
echo "Test starting..."
if test -e "123"; then
echo hi
else
echo hello
fi
head -c 50 /dev/urandom
printf "\n"
cat << EOF
123
456
789
EOF

i=0
while [ $i -le 100 ]; do
printf "%s hello world\n" $i
i=$((i+1))
done
```
I get those time results:
dash: `dash test.sh 0.00s user 0.01s system 95% cpu 0.007 total`
mrsh: `mrsh test.sh 0.15s user 0.06s system 102% cpu 0.205 total`

That's a very significant amount of `~30 times` the amount that dash takes to run the script, and when running it a few times, I got similar results. You can even humanly feel the script in mrsh to take some time while in dash, it basically completes instantly.