`platform_common.h` already has a declaration for BH_VPRINTF so we can
get rid of the one in `platform_internal.h`. Also add some explicit
casts to avoid MSVC compiler warnings.
This folder contains the platform abstract layer for multiple platforms. To support a new platform, you can simply create a new folder here and implement all the APIs defined in include folder.
Refer to port_wamr.md for how to port WAMR to a target platform.