Zephyr deprecated and then removed its stack_analyze function because it
was unsafe. Use the new zephyr thread analyzer instead and rename the
MicroPython function to zephyr.thread_analyze() to be more consistent with
the implementation.
Tested on mimxrt1050_evk.
The output now looks like this:
>>> zephyr.thread_analyze()
Thread analyze:
80004ff4 : unused 400 usage 112 / 512 (21 %)
rx_workq : unused 1320 usage 180 / 1500 (12 %)
tx_workq : unused 992 usage 208 / 1200 (17 %)
net_mgmt : unused 656 usage 112 / 768 (14 %)
sysworkq : unused 564 usage 460 / 1024 (44 %)
idle : unused 256 usage 64 / 320 (20 %)
main : unused 2952 usage 1784 / 4736 (37 %)
The zephyr build system supports merging application-level board
configurations, so there is no need to reproduce this functionality in
MicroPython.
If CONF_FILE is not explicitly set, then the zephyr build system looks for
prj.conf in the application directory. Therefore we rename the MicroPython
prj_base.conf to prj.conf.
Furthermore, if the zephyr build system finds boards/$(BOARD).conf in the
application directory, it merges that configuration with prj.conf.
Therefore we rename all the MicroPython board .conf files and move them
into a boards/ directory.
The minimal configuration, prj_minimal.conf, is left in the application
directory because it is used as an explicitly set CONF_FILE in
make-minimal.
