Issue #9293 has been reported by usa (Usaku NAKAMURA).
Backport #9293: please backport r42282 (compile error with newer bison)
Author: usa (Usaku NAKAMURA)
2.0.0 and 1.9.3 have been already backported the patch.
The Changelog says about bison 3.0, but I found that there is the same
problem with bison 2.7.12.