This simplifies the shebang function significantly. Before, it was
optimized for two characters input. Any module actually parsed should
however have more characters than just the shebang.
The performance stays the same as before.

The current caching logic broke by [0] because it used destructuring
on the module arguments. Since the exported property is a primitive
counting it up or down would not have any effect anymore in the module
that required that property.

The original implementation would cache all stat calls caused during
bootstrap. Afterwards it would clear the cache and lazy require calls
during runtime would create a new cascading cache for the then
loaded modules and clear the cache again.
This behavior is now restored. This is difficult to test without
exposing a lot of information and therfore the existing tests have
been removed (as they could not detect the issue).

With the broken implementation it caused each module compilation to
reset the cache and therefore minimizing the effect drastically.

[0] nodejs#19177

Co-Authored-By: BridgeAR <ruben@bridgewater.de>

This reverts commit 512210f.