crt: Deinline UCRT _swprintf() and _vswprintf() functions and define import symbols for them This allows to reference _swprintf() and _vswprintf() functions for UCRT build via their symbols, like for msvcrt builds. This change is needed to allow to use __MINGW_ASM_CALL(_swprintf). Signed-off-by: Martin Storsjö <martin@martin.st>