py-xdis: updated to 4.4.0

4.4.0:
Incompatibility: load_module() and load_module_from_file_object() now return a couple more parameters: is_pypy, and the sip_hash value when that is available. The timestamp and file_size returned on these functions is now None when they aren't available. Previously timestamp had been 0.

--asm option fixes
Show sip hash in 3.7+ when that is used
Handle PEP 552 bytecode-file variations more properly
Detect more intermediate Python versions in load_code_from_file_object()
3.8+ posonlyargcount in assembly... rename Kw-only field to Keyword-only
Add 3.5 canonic bytecode version Marshal dumps()
convert from byte() to str() in dumps() when needed in 3.x
to_native() convert to bytes from string when needed in 3.x.
clean up loading code by using float version values rather than magic values

(adam)