There is no need to take src_len and dest_len arguments. The case of
reading-only with a single output byte (originally src_len=1, dest_len>1)
is now handled by using the output buffer as the input buffer, and using
memset to fill the output byte into this buffer. This simplifies the
implementations of the spi_transfer protocol function.
Similar to how binary op already works. Common unary operations already
have fast paths for bool so there's no need to have explicit handling of
ops in bool_unary_op, especially since they have the same behaviour as
integers.
On 32-bit archs this makes the scope_t struct 48 bytes in size, which fits
in 3 GC blocks (previously it used 4 GC blocks). This will lead to some
savings when compiling scripts because there are usually quite a few scopes,
one for each function and class.
Note that qstrs will fit in 16 bits, this assumption is made in a few other
places.
The memory read/write I2C functions now take an optional keyword-only
parameter that specifies the number of bits in the memory address.
Only mem-addrs that are a multiple of 8-bits are supported (otherwise
the behaviour is undefined).
Due to the integer type used for the address, for values larger than 32
bits, only 32 bits of address will be sent, and the rest will be padded
with 0s. Right now no exception is raised when that happens. For values
smaller than 8, no address is sent. Also no exception then.
Tested with a VL6180 sensor, which has 16-bit register addresses.
Due to code refactoring, this patch reduces stmhal and esp8266 builds
by about 50 bytes.