- remember valid (!) archives (normal case).
- retry invalid archives
- synchronize directly on "invalidArchives" since that is final itself

Change-Id: I4f48d9b635dc5e4fe22938b98be03c2c45346281
Signed-off-by: Joerg Kubitz <jkubitz-eclipse@gmx.de>
Reviewed-on: https://git.eclipse.org/r/c/jdt/eclipse.jdt.core/+/182540
Tested-by: JDT Bot <jdt-bot@eclipse.org>
Reviewed-by: Andrey Loskutov <loskutov@gmx.de>