printf retargetting

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Please provide some way to retarget printf to the uart output, this is necessary with STM8 because the stdperipheral library, of which most function are not implemented in the core, is C and we have to use many of these functions, besides, due to linking issue we have to wrap these STDperipheal library function in separate C files, and obviously we cannot use Serial from C context. The only way is to declare an external C wrapper in the ino (considered as cpp by compiler) an declare external in the C files, but that cause problem of backward declaration and it is messy and dirty anyway.
Providing a proper retargetting of printf would at least solve this problem.