Does any C library implement C11 threads for GNU/Linux?

Question

There have been a lot of questions about C11 and C11 threading, but I don't see a definitive answer anywhere:

Does any C library implement the C11 threading interface usable on GNU/Linux-like? e.g., provide the "optional" <threads.h> and the thread support library like thrd_create(), from the C11 standard near p. 376.

Ideally, I'd like to find a library that is common-ish, open-source or free, for common/generic/multi architecture (e.g., GNU/Linux, x86_64, or portable-ish).

A few of the more helpful and relevant SO links:

• this one and this one on glibc;
• this one that's talking about the standard;
• this one about clang;
• this one about C11 in general and this one about Windows and other platforms;
• a lot more about C++11 threading, but I am only interested in C11.

Some non-starter options for libraries:

• glibc library does not; there is an open bug since 2012; there was GSoC proposal but seems not accepted;
• LLVM/Clang project does not have a C library;
• musl library does not; -- now does! See edit below and answer.
• Newlib library supports threading (docs), but not using pthread nor C11 threads;
• uClibc does not;
• this comparison chart, which is dubious (e.g., I see no evidence in musl sources for C11 thread-local storage support);
• Some various posts about BSD,
• Pelles, which appears closed and Windows-only.

I am not interested in POSIX threads (many fine options), Windows, an IDE, nor C++11 (I know that GNU libstdc++ and LLVM/Clang libc++ provide C++11's std::thread, which uses -pthread)

Thanks!

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(re-)Edit: question re-opened, so migrated content to answer to clean up.

Answer 1

musl now (as of Sep 2014-ish) implements C11 threads!

According to this recent musl mailing list post and other conversation on that list in Jul-Sep 2014, it appears that the musl library now (as of 2014-09-07) implements the C11 threads interface, though the comparison chart; does not as of this writing reflect this.

Since this question is re-opened, I moved this content to a proper answer.