C11 defects: initialization of atomic_flag

With this post I will be starting some random collection of things that I consider being defects of the C11 standard. Perhaps someone of the committee could pick them up or send me a mail to discuss them and eventually formulate a formal defect report.

C11 expresses the intention to have atomic_flag as a primitive that should allow to emulate all other atomic types and operations, 7.17.8 p3 in a note says:

The remaining types can be emulated with atomic_flag, though with less than ideal properties.