This reverts commit e0eca262852dba1a78afcde64a49126c81fead1a.

free_filename is used by the wincache extension, restore this
field for PHP 7.4.

Symbols are not used in the current code.

Also remove not needed ocijdbc8 library addition and checks whcih were
removed also via b8e1d4d4e5af74a9d5a95d03adbe2b93e58301b7 so Oracle 8
is no longer supported.

Closes GH-4454

The php_stream_read() and php_stream_write() functions now return
an ssize_t value, with negative results indicating failure. Functions
like fread() and fwrite() will return false in that case.

As a special case, EWOULDBLOCK and EAGAIN on non-blocking streams
should not be regarded as error conditions, and be reported as
successful zero-length reads/writes instead. The handling of EINTR
remains unclear and is internally inconsistent (e.g. some code-paths
will automatically retry on EINTR, while some won't).

I'm landing this now to make sure the stream wrapper ops API changes
make it into 7.4 -- however, if the user-facing changes turn out to
be problematic we have the option of clamping negative returns to
zero in php_stream_read() and php_stream_write() to restore the
old behavior in a relatively non-intrusive manner.

New fix for bug #78263. This is special-cased elsewhere in the engine,
so we need to mirror it here.

This reverts commit 428cfdd1810b17f0064b7691276f0eb92dc963b6.

Symbol is not used anywhere in the code and also Postgresql 7.x is
EOL anyway.

Closes GH-4453