llvm-project

52fd3ec2 - [libc] Define _POSIX_THREADS and support _SC_THREADS in sysconf (#201091)

[libc] Define _POSIX_THREADS and support _SC_THREADS in sysconf (#201091) Defined the _POSIX_THREADS macro to 202405L in unistd-macros.h for Linux to signal POSIX thread support. Also implemented runtime support for _SC_THREADS in sysconf, returning _POSIX_THREADS, and added _SC_THREADS and _POSIX_THREADS to the public unistd.yaml specification. Added compile-time and runtime tests to verify _POSIX_THREADS definition and sysconf(_SC_THREADS) behavior. Standardized header comments in unistd-macros.h to conform to LLVM style. Assisted-by: Automated tooling, human reviewed. --------- Co-authored-by: Pavel Labath <pavel@labath.sk>