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.

Previously this generated a notice, but would likely generate an
Error when unserializing.

Now we treat it with the same distinction as direct property
accesses, i.e. referencing an unset/undefined normal property
stays a notice, while a typed property becomes an Error exception.

This fixed bug #79002.

Closes GH-5050.

Empty merge.

This reverts commit 17a9f1401aeb35fe1e3657b38102a410d151d42f, because
this commit would break ABI, and also due to bug #79013.
We keep the commit for PHP 7.4+, though.

* PHP-7.3:
  Fix #54298: Using empty additional_headers adding extraneous CRLF

If the header string is empty, we pass `NULL` to `php_mail()` to avoid
further checks on the string length.

OpenSSL 1.1 does not need crypto locking callbacks, so avoid
detecting and linking against it in the first place.

* PHP-7.3:
  Fix #79068: gdTransformAffineCopy() changes interpolation method