Xtensa ESP32: Need to spill registers to memory as the last dying action before switching to a new thread.

Fix context save logic when called in window ABI configuration. Add an IDLE stack.  Don't depend on the mystery stack received from the bootloader.

Xtensa ESP32: Need to clone some logic for syncrhonous context switch.  Window spill logic in the conmon restores logic is inappropriate in this context

BugFix:uart_ops_s portion of cdcacm will not be initalized with correct functions if CONFIG_SERIAL_DMA is lit.

C&P error from F7

BugFix:uart_ops_s portion of cdcacm will not be initalized with correct functions if CONFIG_SERIAL_DMA is lit.

    This fixes the issses in a C99 compatible way

Xtensa ESP32: Fixes a few issue with restoring registers on interrupt return, but there is still a problem

Back out most of 46dbbe83.  The order is correct -- or, rather, the order is the same as the order that response data is provided.  Change the order will break all other drivers.

MMC/SD:  Format changed from %d to %lu.  Must cast argument to unsigned long to avoid crash on 64-bit machine.

MMC/SD SDIO (again): This is really an endian-ness issue.  Behavior should be different on big- vs little-endian machines.

Add missing ENTRY() and RET() macros in C callable assembly language.  At one time I though the that the ESP32 support the CALL0 ABI.  I was mistaken so there may be a few more like this.