Fix quick fly2iceland after rebase.

Change-Id: I844f005782b3ecdcb52dc2484d44f4ae34e1c670
diff --git a/src/compiler_llvm/compiler_llvm.h b/src/compiler_llvm/compiler_llvm.h
index dabd7be..e9ccd4d 100644
--- a/src/compiler_llvm/compiler_llvm.h
+++ b/src/compiler_llvm/compiler_llvm.h
@@ -98,8 +98,8 @@
 
   InstructionSet insn_set_;
 
-  Mutex num_cunits_lock_;
-  size_t num_cunits_;
+  Mutex num_cunits_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
+  size_t num_cunits_ GUARDED_BY(num_cunits_lock_);
 
   std::string bitcode_filename_;