Due to ASLR restrictions, preloading on Windows does not work with
any code that has preloading dependencies on internal classes.
This effectively makes it unusable for any non-trivial codebase.
Instead of pretending like preloading is going to work, only to
make people realize that it really doesn't once they get beyond
a dummy example, we disable support for preloading on Windows
entirely.
Closes GH-4999.
During preloading, check that all classes that have been included
as part of the preload script itself (rather than through opcache_compile_file)
can actually be preloaded, i.e. satisfy Windows restrictions, have
resolved initializers and resolved property types. When resolving
initializers and property types, also autoload additional classes.
Because of this, the resolution runs in a loop.
