Remove unused build specific symbols

Remove unused build specific symbols

These were part of the following decomissioned extensions:
- PHP_SYBASE part of the sybase extension
- PHP_MSQL_* part of the msql extension
- PHP_APACHE_* symbols were used in apache and apache_hooks sapis
- PHP_FHTTPD_* symbols part of old sapi/fhttpd
- PHP_MYSQL_* symbols were part of the legacy mysql extension

- Remove PHP_ORACLE_* symbols
  These were part of the obsolete oracle extension that was moved to PECL
  via f35af61ef8fd10f2d1bada1909e888293fb519b8.

- PHP_OCI8_SHARED_LIBADD and PHP_OCI8_DIR were removed via
  c33f88ccb08ca05ebf822ef94cb3fa41a1838226

And other are not used anywhere across the php-src codebase