* call-frame:
Simplify call-frame handling
Removed EG(active_symbol_table) and use corresponding value from EG(current_execute_data)
Use values from current_execute_data instead of globals where possible
Removed EG(called_scope) and use corresponding value from EG(current_execute_data)
Removed EG(in_execution). If EG(currentent_execute_data) is not NULL we are executing something.
Removed EG(opline_ptr) and use corresponding value from EG(current_execute_data)
Removed EG(active_op_array) and use corresponding value from EG(current_execute_data)
Uinified call frame handling for user and internal functions. Now EG(current_execute_data) always point to the call frame of the currently executed function.
Fixed cleanup of incompleytely passed parameters
Prohibited parameter redefinition
Fixed support for extra arguments in conjunction with variadiv argument. Use compile time flags to check if we call constructor and result of ZEND_NEW is used or not.
Fixed uninitialized variables
Optimization
Changed zend_execute_data layout to reduce memory overhead
Help C compilet to do the better job optimizing target code
Use fast comparison for (func->type == ZEND_USER_FUNCTION || func->type == ZEND_EVAL_CODE)
Keep extra args in the same VM stack segment (after all CV and TMP vars)
Refactoring: merge call_frame and end_execute_data into single data structure. Keep only single copy of each argument on VM stack (previously ZE kept two copies of each arguments for user functions)
Refactoring: use call_frames instead of call_slots
Conflicts:
Zend/zend_vm_def.h
Zend/zend_vm_execute.h
In PHP-5.6 and below each argument passed to user function was copies on VM stack twice.
Now we always have ZEND_INIT_FCALL (or simular) opcode that pushes "call frame" on top of VM stack.
"Call frame" is actually the same zend_execute_data structure.
All the following ZEND_SEND instructions push arguments on top of the stack in a way that they directly comes into corresponding CV variables of the called frame. Extra arguments are copied at the end of stack frame (after all CV and TMP variables) on function enterance.
There are two minor incompatibilities:
1) It's not allowed to decalre functions redefining arguments e.g. "function foo($a,$a) {}".
2) func_get_arg() and func_get args() return the current value of argument and not the original value that was sent.
