This reduces code duplication and allows to make mp_classify_fp_as_int
static, which reduces code size.

This should be a little more efficient (since we anyway scan the input
packet for the interrupt char), and it should also fix any non-atomic read
issues with the buffer state being changed during an interrupt.

Throughput tests show that RX rate is unchanged by this patch.

The previous timeout value of 150ms could lead to data being lost (ie never
received by the host) in some rare cases, eg when the host is under load.
A value of 500ms is quite conservative and allows the host plenty of time
to read our data.

It will be reused e.g. for accept() implementation.

Hashing of float and complex numbers that are exact (real) integers should
return the same integer hash value as hashing the corresponding integer
value.  Eg hash(1), hash(1.0) and hash(1+0j) should all be the same (this
is how Python is specified: if x==y then hash(x)==hash(y)).

This patch implements the simplest way of doing float/complex hashing by
just converting the value to int and returning that value.

Disabled by default.

Used e.g. by Zephyr port.

Should be skipped on missing uso, uerrno modules.

This restores ability to run testsuite with 16K heap.

Split this setting from MICROPY_CPYTHON_COMPAT. The idea is to be able to
keep MICROPY_CPYTHON_COMPAT disabled, but still pass more of regression
testsuite. In particular, this fixes last failing test in basics/ for
Zephyr port.

So underlying device was properly closed too.

Some "device" implementations may be sensitive to this.

Short read approach is taken - at most, the remaining data in the current
fragment will be returned.

The first memmove now copies less bytes in some cases (because len_adj <=
slice_len), and the memcpy is replaced with memmove to support the
possibility that dest and slice regions are overlapping.

The foundation of recv() support is per-socket queue of incoming packets,
implemented using Zephyr FIFO object. This patch implements just recv()
for UDP, because TCP recv() requires much more fine-grained control of
network fragments and handling other issues, like EOF condition, etc.

It can still be overwritten by a port in mpconfigport.h but for almost
all cases one can use the provided default.

This follows the pattern of how all other headers are now included, and
makes it explicit where the header file comes from.  This patch also
removes -I options from Makefile's that specify the mp-readline/timeutils/
netutils directories, which are no longer needed.

Such constants are MCU specific so shouldn't be specified in the board
config file (else it leads to too much duplication of code).

This patch also adds I2C timing values for the F767/F769 for 100k, 400k
and 1MHz I2C bus frequencies.

So far, socket creation and closure is implemented.

Requires inclusion of zephyr.h to properly detect that we're building for
Zephyr.

Not all F7 MCUs have SDMMC2.