Fix typo in SwiftPrivateThreadExtras.

Co-Authored-By: Sergej Jaskiewicz <[email protected]>

Author: 3405691582

stdlib/private/SwiftPrivateThreadExtras/SwiftPrivateThreadExtras.swift

@@ -17,7 +17,7 @@
 
 #if os(macOS) || os(iOS) || os(watchOS) || os(tvOS)
 import Darwin
-#elseif os(Linux) || os(FreeBSD) || os(OpenBSD) || os(Android) || os(Cygwin) || os(Haiku)
+#elseif os(Linux) || os(FreeBSD) || os(OpenBSD) || os(PS4) || os(Android) || os(Cygwin) || os(Haiku)
 import Glibc
 #elseif os(Windows)
 import MSVCRT