Eliminates clang warnings:
cppsetup.c:41:30: warning: cast from 'char *' to 'struct _parse_data *'
  increases required alignment from 1 to 8 [-Wcast-align]
    struct _parse_data *pd = (struct _parse_data *) ip->data;
                             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cppsetup.c:69:30: warning: cast from 'char *' to 'struct _parse_data *'
  increases required alignment from 1 to 8 [-Wcast-align]
    struct _parse_data *pd = (struct _parse_data *) ip->data;
                             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>