This moves them from ``.data`` to ``.rodata`` and allows more compiler optimizations.
* ext/opcache/zend_accelerator_hash: make prime_numbers const
* Zend/zend_signal: make zend_sigs const
* ext/dba: make dba_handler pointers const
* ext/exif: make php_tiff_bytes_per_format and other globals const
* ext/intl/grapheme: make grapheme_extract_iters const
* ext/mstring: make rare_codepoint_bitvec const
* ext/snmp: make objid_mib const
* ext/opcache: make all zend_shared_memory_handlers const