Merge r309875 into the 5.0 branch: Move lock acquire/release functions in task deque cleanup code

[hahnjo]

Bugzilla Link	35167
Resolution	FIXED
Resolved on	Nov 14, 2017 11:11
Version	unspecified
OS	All
Blocks	#33840
CC	@AndreyChurbanov,@jpeyton52,@tstellar
Fixed by commit(s)	r309875 r318171

Extended Description

The original locations can be reached without initializing the lock variable
(td_deque_lock), so it is potentially unsafe. It is guaranteed that the lock
is initialized if the deque (td_deque) is not NULL, and lock functions can be
safely called.

[hahnjo]

assigned to @AndreyChurbanov

[tstellar]

Hi Andrey,

Is this OK to merge to the release_50 branch: https://reviews.llvm.org/rL309875

[AndreyChurbanov]

Yes, it is OK to merge.

[tstellar]

Merged: r318171