Avoid a possible thread sync issue.

Could be that it's about to wake listsync, does, and then we wait.
Oops, left these here.
Don't wait directly from GPUCommon, do it in sceGe.

Makes debugging a bit easier.
SyncThread before deciding if the fbo is dirty.

Fixes fps drops in yet other games with multithreading enabled.
Use a possibly harmless hack to prevent hangs.

Not sure where the problem is, but this fixes it pretty consistently for
me... seems like lists are somehow not being processed after becoming
processable?
Fix some potential threading probs with SymbolMap.

Got some strange crashes.
As a safety, especially for win32, cap the wait.
Merge pull request #3120 from unknownbrackets/gpu-thread

Fix some more GPU thread sync issues