samba: fix parsing linemarkers in preprocessor output

When PIDL calls out to C preprocessor to expand IDL files
and parse the output, it filters out linemarkers and line control
information as described in http://gcc.gnu.org/onlinedocs/cpp/Preprocessor-Output.html
and http://gcc.gnu.org/onlinedocs/cpp/Line-Control.html#Line-Control



With gcc 4.8 stdc-predef.h is included automatically and linemarker for the
file has extended flags that PIDL couldn't parse ('system header that needs to
be extern "C" protected for C++')

Signed-off-by: Yue Tao <Yue.Tao@windriver.com>
Signed-off-by: Chong Lu <Chong.Lu@windriver.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>