GHC.Conc.Sync: Pass TSO to stackOverflow

Signed-off-by: Austin Seipp <aseipp@pobox.com>
length001 passes now

It no longer stack overflows, since the stack is infinite by default
now.

Signed-off-by: Austin Seipp <aseipp@pobox.com>
EventManager: Gracefully handle an initial 'Finished' state (#8235)

Signed-off-by: Andreas Voellmy <andreas.voellmy@gmail.com>
Revert "GHC.Conc.Sync: Pass TSO to stackOverflow"

This reverts commit 0cfba06e09cae209c6fc1f94edd815ccf5a7e9d7.
Revert "length001 passes now"

This reverts commit 1be0171fc8c911a7ce3d1e3926475e789d077724.
Redo <= with a type synonym instead of a class, add instance for boolean singletons, remove (-)