Basic support for overlay databases #3881

Job	Run time
Diagnostic export (ubuntu-latest, linked)	1m 4s
Diagnostic export (ubuntu-latest, nightly-latest)	1m 30s
Diagnostic export (windows-latest, linked)	3m 0s
Diagnostic export (macos-latest, linked)	1m 6s
Diagnostic export (macos-latest, nightly-latest)	1m 44s
Diagnostic export (windows-latest, nightly-latest)	4m 10s
	12m 34s

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