parsing_cocci: ast0: Make Attibute in SmPL's AST more general
This patch changes the structure of 'Attribute'. In order to support attribute later, the current Attribute needs to be refactored into a more general structure.
SmPL's ast structure(current): __foo => Attribute( __foo) or MetaAttribute (__foo)
SmPL's ast structure(proposed): __foo => Attribute( AttrName (__foo) ) or Attribute( MetaAttr (__foo) )
C's ast structure(current): foo => Attribute( foo )
C's ast structure(proposed): foo => Attribute( AttrName(foo) )
Signed-off-by: Keisuke Nishimura mumumu0722@gmail.com