Use the previous resolved binary type info (obj_data->target_info.bin_type) to
check the endian and bit-width but not the raw binary info, the latter is not
suitable for the check for Win32 object file type.
And fix the symbol comparison issue in resolve_target_sym(), as in Win32, the
symbol name of a function added by LLVMAddFunction() is prefixed by '_',
which leads to invalid result returned by strcmp().