cc: add += and function pointers

tools/cc.py

@@ -376,6 +376,10 @@ class CcTransform(lark.visitors.Transformer):
         pointed = children[-1]
         return PointerType(volatile=volat, pointed=pointed)
 
+    def funptr_type(self, children):
+        ret, *params = children
+        return FunType(ret=ret, params=params)
+
     def comma_expr(self, children):
         c1, c2 = children
         if c1.data == 'comma_expr':
@@ -1279,6 +1283,7 @@ class CcInterp(lark.visitors.Interpreter):
         return f
 
     or_ass = _assign_op('_or')
+    add_ass = _assign_op('add')
 
     def _forward_op(self, tree):
         self.visit_children(tree)