With a sample set of 1, I have detemined that there is about 30% tax
caused by asynchronous functions in the compiler. The `typescript`
compiler itself is fully synchronous, and we basically moved to do the
same, and this turns out reducing the amount of time wasted in the
runloop and in promise bookeeping.

Tested on `aws-cdk-lib`, it turns out to be reducing the compile time
from ~142 seconds to ~100 seconds.