Fix array_pop
Fix array_pop

Code:
$var = ['AAAAA'];
array_pop($var);

Error:
java.lang.ArrayIndexOutOfBoundsException: -1
livingvirus/jphp,livingvirus/jphp,jphp-compiler/jphp,livingvirus/jphp,livingvirus/jphp,jphp-compiler/jphp,livingvirus/jphp,jphp-compiler/jphp,jphp-compiler/jphp