Our header verification tool caught incorrect headers in files added by JDK-8254315:

BAD COPYRIGHT: /jdk_git/open/src/hotspot/share/gc/shenandoah/shenandoahMarkBitMap.cpp
BAD COPYRIGHT: /jdk_git/open/src/hotspot/share/gc/shenandoah/shenandoahMarkBitMap.hpp
BAD COPYRIGHT: /jdk_git/open/src/hotspot/share/gc/shenandoah/shenandoahMarkBitMap.inline.hpp
BAD COPYRIGHT: /jdk_git/open/src/hotspot/share/gc/shenandoah/shenandoahReferenceProcessor.cpp
BAD COPYRIGHT: /jdk_git/open/src/hotspot/share/gc/shenandoah/shenandoahReferenceProcessor.hpp
5 header format error(s).

They are missing next line:

* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.