This patch implements support for class methods __delattr__ and __setattr__
for customising attribute access. It is controlled by the config option
MICROPY_PY_DELATTR_SETATTR and is disabled by default.
A few tests still fail on PYBLITE, and that's due to differences in the
available peripheral block numbers on the different MCUs (eg I2C(2)
exists on one, but it's I2C(3) on the other).
This new function controls what happens on a hard-fault:
- debugging disabled: board will do a reset
- debugging enabled: board will print registers and stack and flash LEDs
The default is disabled, ie to do a reset. This is different to previous
behaviour which flashed the LEDs and waited indefinitely.
machine.time_pulse_us() is intended to provide very fine timing, including
while working with signal bursts, where each transition is tracked in row.
Throwing and handling an exception may take too much time and "signal loss".
So instead, in case of a timeout, just return negative value. Cases of
timeout while waiting for initial signal stabilization, and during actual
timing, are recognized.
The documentation is updated accordingly, and rewritten somewhat to clarify
the function behavior.
Updated modbuiltin.c to add conditional support for 3-arg calls to
pow() using MICROPY_PY_BUILTINS_POW3 config parameter. Added support in
objint_mpz.c for for optimised implementation.