Fixes after sync freeze on MacOS

[LeFrosch]

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Discussion thread for this change

Issue number:

Description of this change

CLion freezes every time after sync because the XcodeCompilerSettings are resolved under read lock.

I think we can drop the read lock for the entire workspace update since as far as I can tell nothing actually requires a read lock. And the actual update of the workspace is performed under write lock.

Or we could just move the compiler settings resolution before the read lock is taken. But dropping the read lock might prevent freezes in future.

[ujohnny]

I see that a while ago RA was pushed down in a045eab, but I'm not sure what part of update actually requires RA. Is it so that no runtime warnings for missing RA are reported? It could be that OCWorkspace.getConfigurations requires it, but it's not mentioned in the doc.

[ujohnny]

The purpose of removed RA is unclear to me and it's not required by the code called.