Indeed the HAL does not need to be mucked around with to expose ATmega2560 pins not available as numbers on the MEGA board, I'll need to update the wiki with that tidbit and a reference to the pin-mapping comment in `fastio_1280.h`.

Co-Authored-By: ejtagle <ejtagle@hotmail.com>

- Ordering and match classification between `boards.h` and `pins.h`
- Check `pins.h` environments

STM32 ARM Cortex-M3 boards were listed as M4

As noted in #10777

Use macros that explicitly avoid double-evaluation and can be used for any datatype, replacing `min`, `max`, `abs`, `fabs`, `labs`, and `FABS`.

Co-Authored-By: ejtagle <ejtagle@hotmail.com>

Co-Authored-By: ejtagle <ejtagle@hotmail.com>

As mentioned in https://github.com/MarlinFirmware/Marlin/issues/9429#issuecomment-385305597

Co-Authored-By: Jack Bradach <jack@bradach.net>

Co-Authored-By: Bob-the-Kuhn <bob-the-kuhn@users.noreply.github.com>

…and any other platforms where `false`/`true` are defined as `0x0`/`0x1`.

This fixes issue #10550.