ThreadSanitizer has trouble understanding that gluelist->glue is
constant after it is assigned to the slabheader with cmpxchg. Help
ThreadSanitizer to understand the code by using CMM_STORE_SHARED and
CMM_LOAD_SHARED on gluelist->glue.
Merge branch 'ondrej/hint-tsan-in-addglue' into 'main'