Merge pull request #5 from ilyk/master

Added $expression to logger::warning call
method_exists optimizer, use non-tracked zvals for property update constants
Merge pull request #6 from ilyk/master

some additions
fix method_exist optimizer, pass parameters by reference in internal methods
enable method cache [ci skip]
remove cache, avoid extra alloc in fcall, fixes [ci skip]
method cache [ci skip]