g1HeapVerifier.cpp redundantly #includes g1CollectedHeap.hpp and heapRegions.hpp, because it also #includes g1CollectedHeap.inline.hpp and heapRegions.inline.hpp.

g1FullGCOopClosures.inline.hpp #includes g1Allocator.hpp when it should #include g1Allocator.inline.hpp to future-proof it.

memoryService.hpp's copyright date should be updated form 2017 to 2018, since it was last changed in June 2018.