Merging r276015:

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r276015 | vedantk | 2016-07-19 13:16:08 -0700 (Tue, 19 Jul 2016) | 7 lines

[tsan] Don't instrument __llvm_gcov_global_state_pred or __llvm_gcda*

r274801 did not go far enough to allow gcov+tsan to cooperate. With this
commit it's possible to run the following code without false positives:

  std::thread T1(fib), T2(fib);
  T1.join(); T2.join();
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llvm-svn: 276810