* optionally move float emulation code into iram
allows doing float operation in iram
suitable for libraries like AccelStepper when called from ISR
* proposed changes for pio from @mcspr
* Update documentation
Describe how to improve Exception Decoder results.
Updated build option details.
* Added d-a-v's code. And updated description and debug macro.
* Update doc
Updated platform.txt - positioned -Os such that it can be overridden by `build.opt`.
Add suggestion of using `-Og` which may improve the Decoder's line number correlation
with the problem in the source code.
Untested adjustments to platformio-build.py
* Fixed code formatting
* Fixed example
Previously `-O3` in the example had no effect. It was overridden by later flags.
Reording the `-Os` allowed changing optimization to work. Somehow this triggered
a new warning "Stream.h:50:7: warning: 'f.Stream::_startMillis' may be used
uninitialized in this function". Replaced `-O3` with `-Og`.
* Proposed "Debug port" menu change
Preserves a pathway for `build.opt` override.
* Update boards.txt.py and docs - WIP
* Improve organization of optimization content.
Use "Debug Optimization" for menu name.
The menu item defines the initial optimization.
platform.txt - optimization parameter can be overridden by build.opt.
* Add fallback value for build.debug_optim to platform.txt
* update text and undo changes to platformio-build.py
* tweak text
* Added ':orphan:' mark to a06-global-build-options.rst
* Update doc. Added link in page index to 'Improving Exception Decoder Results'
* Update text to reference PR#8868 improvements for leaf function.
Remove nonos-sdk-v2.2.0-28-g89920dc aka 3v0, since we have a real v3
Remove 3.0.0...3.0.4 to reduce overhead in maintaining a bunch or binary patches
Update our docs and menu opts to mention 'experimental' status
Old versions still remains in git history, so anyone wanting to play around with 3.0.x could still make use of that work
