All source files include general.h first and before anything else.
This inlcludes platform.h and platform_support.h
No header file needs to include to include any of these, but should include
any others needed for it's own declarations.
This reverts commit 32b909067b2a34f475a52585b965c195de87c172.
This CRC routine doesn't work. The bit order used by the
STM32 CRC unit is reveresed from what GDB uses.