* Update signature of pcre API
This changes the variables that are bools to actually be bools instead
of ints, which allows some additional optimization by the compiler (e.g.
removing some ternaries and move extensions).
It also gets rid of the use_flags argument because that's just the same
as flags == 0. This reduces the call frame.
* Use zend_string_release_ex where possible
* Remove duplicate symbols from strchr
* Avoid useless value conversions
* Use a raw HashTable* instead of a zval
* Move condition
* Make for loop cheaper by reusing a recently used value as start iteration index
* Remove useless condition
This can't be true if the second condition is true because it would
require the string to occupy the entire address space.
* Upgrading + remark