implements($method)- Always true for vtables.
body($method, $line, $out_name)- Returns the C code for the method body.
$line is used to accumulate the number of lines,
$out_name is the name of the output file we are generating.
- Overrides the default implementation to direct all unknown methods to first check if there is an implementation of the vtable method in the vtable methods hash of this class of any others,
and delegates up to any PMCs in the MRO.
