Hi Mandy, thanks for reviewing! I think Erik Ö. already pushed it for me.
A minor comment that GCMemoryManager could take an enum to indicate the type of this GC action (major vs minor). This can be a future cleanup.
This may be overly restrictive: some GCs may not necessarily provide a major/minor distinction, but have only one GC manager (e.g. epsilon), or may provide 3 or more GC managers (e.g. 'minor' partial (or young) GC, 'intermediate' concurrent GC, 'intermediate or major' concurrent full GC, 'major' STW last-ditch full GC...).
Roman
