Fixes and improvements to `int.to_bytes()` are:
- No longer overflows if byte size is 0 (closes#13041).
- Raises OverflowError in any case where number won't fit into byte length
(now matches CPython, previously MicroPython would return a truncated
bytes object).
- Document that `micropython int.to_bytes()` doesn't implement the optional
signed kwarg, but will behave as if `signed=True` when the integer is
negative (this is the current behaviour). Add tests for this also.
Requires changes for small ints, MPZ large ints, and "long long" large
ints.
Adds a new set of unit tests for ints between 32 and 64 bits to increase
coverage of "long long" large ints, which are otherwise untested.
Tested on unix port (64 bit small ints, MPZ long ints) and Zephyr STM32WB
board (32 bit small ints, long long large ints).
This work was funded through GitHub Sponsors.
Signed-off-by: Angus Gratton <angus@redyak.com.au>
Tests which don't work with small ints are suffixed with _intbig.py. Some
of these may still work with long long ints and need to be reclassified
later.
