base: define _CFThreadCreate for windows

Define _CFThreadCreate in terms of _beginthreadex on Windows rather than
pthread_create.

Author: compnerd

CoreFoundation/Base.subproj/CFPlatform.c

@@ -27,6 +27,7 @@
 #include <shlobj.h>
 #include <WinIoCtl.h>
 #include <direct.h>
+#include <process.h>
 #define SECURITY_WIN32
 #include <Security.h>
 
@@ -1368,9 +1369,15 @@ void _CFThreadSpecificSet(_CFThreadSpecificKey key, CFTypeRef _Nullable value) {
 }
 
 _CFThreadRef _CFThreadCreate(const _CFThreadAttributes attrs, void *_Nullable (* _Nonnull startfn)(void *_Nullable), void *_CF_RESTRICT _Nullable context) {
+#if DEPLOYMENT_TARGET_WINDOWS
+    return (_CFThreadRef)_beginthreadex(NULL, 0,
+                                        (_beginthreadex_proc_type)startfn,
+                                        context, 0, NULL);
+#else
     _CFThreadRef thread;
     pthread_create(&thread, &attrs, startfn, context);
     return thread;
+#endif
 }
 
 CF_CROSS_PLATFORM_EXPORT int _CFThreadSetName(_CFThreadRef thread, const char *_Nonnull name) {