Remove dead code (gccxml)

This was a special case for gccxml. We are dropping
gccxml support in the next release so this can be removed.

Author: iMichka

pygccxml/declarations/decl_printer.py

@@ -107,10 +107,6 @@ def instance(self, inst):
     def is_builtin_decl(decl):
         if not decl.name.startswith('__builtin_'):
             return False
-        # FIXME: This won't probably not work with CastXML.
-        # It either needs to be removed or improved
-        return decl.location and decl.location.file_name \
-            and decl.location.file_name.endswith('gccxml_builtins.h')
 
     @staticmethod
     def __nice_decl_name(inst):