[all-commits] [llvm/llvm-project] f74f21: Always use pthread_rwlock on Apple platforms (#70151)

[cooperp via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: f74f2133d3c6f746563da101250fdb599aacfa94
      https://github.com/llvm/llvm-project/commit/f74f2133d3c6f746563da101250fdb599aacfa94
  Author: cooperp <peter_cooper at apple.com>
  Date:   2023-10-26 (Thu, 26 Oct 2023)

  Changed paths:
    M llvm/include/llvm/Support/RWMutex.h

  Log Message:
  -----------
  Always use pthread_rwlock on Apple platforms (#70151)

pthread_rwlock is faster than std::shared_mutex, especially in heavily
threaded code such as the Swift compiler.

rdar://117445844