bpo-30279: Remove unused Python/thread_foobar.h (#1473)

Python/thread_foobar.h is the template code that is threading adaptation
for new platforms, also hasn't been used on actual platforms.
Python/thread_*.h give concrete examples of adaptation instead of the
template code.

Python/thread.c

@@ -92,12 +92,6 @@ static size_t _pythread_stacksize = 0;
 #endif
 
 
-/*
-#ifdef FOOBAR_THREADS
-#include "thread_foobar.h"
-#endif
-*/
-
 /* return the current thread stack size */
 size_t
 PyThread_get_stacksize(void)

Python/thread_foobar.h

-/*
- * Initialization.
- */
-static void
-PyThread__init_thread(void)
-{
-}
-
-/*
- * Thread support.
- */
-unsigned long
-PyThread_start_new_thread(void (*func)(void *), void *arg)
-{
-    int success = 0;            /* init not needed when SOLARIS_THREADS and */
-                /* C_THREADS implemented properly */
-
-    dprintf(("PyThread_start_new_thread called\n"));
-    if (!initialized)
-        PyThread_init_thread();
-    return success < 0 ? PYTHREAD_INVALID_THREAD_ID : 0;
-}
-
-unsigned long
-PyThread_get_thread_ident(void)
-{
-    if (!initialized)
-        PyThread_init_thread();
-}
-
-void
-PyThread_exit_thread(void)
-{
-    dprintf(("PyThread_exit_thread called\n"));
-    if (!initialized)
-        exit(0);
-}
-
-/*
- * Lock support.
- */
-PyThread_type_lock
-PyThread_allocate_lock(void)
-{
-
-    dprintf(("PyThread_allocate_lock called\n"));
-    if (!initialized)
-        PyThread_init_thread();
-
-    dprintf(("PyThread_allocate_lock() -> %p\n", lock));
-    return (PyThread_type_lock) lock;
-}
-
-void
-PyThread_free_lock(PyThread_type_lock lock)
-{
-    dprintf(("PyThread_free_lock(%p) called\n", lock));
-}
-
-int
-PyThread_acquire_lock(PyThread_type_lock lock, int waitflag)
-{
-    return PyThread_acquire_lock_timed(lock, waitflag ? -1 : 0, 0);
-}
-
-PyLockStatus
-PyThread_acquire_lock_timed(PyThread_type_lock lock, PY_TIMEOUT_T microseconds,
-                            int intr_flag)
-{
-    int success;
-
-    dprintf(("PyThread_acquire_lock_timed(%p, %lld, %d) called\n", lock, microseconds, intr_flag));
-    dprintf(("PyThread_acquire_lock_timed(%p, %lld, %d) -> %d\n",
-	     lock, microseconds, intr_flag, success));
-    return success;
-}
-
-void
-PyThread_release_lock(PyThread_type_lock lock)
-{
-    dprintf(("PyThread_release_lock(%p) called\n", lock));
-}
-
-/* The following are only needed if native TLS support exists */
-#define Py_HAVE_NATIVE_TLS
-
-#ifdef Py_HAVE_NATIVE_TLS
-int
-PyThread_create_key(void)
-{
-    int result;
-    return result;
-}
-
-void
-PyThread_delete_key(int key)
-{
-
-}
-
-int
-PyThread_set_key_value(int key, void *value)
-{
-    int ok;
-
-    /* A failure in this case returns -1 */
-    if (!ok)
-        return -1;
-    return 0;
-}
-
-void *
-PyThread_get_key_value(int key)
-{
-    void *result;
-
-    return result;
-}
-
-void
-PyThread_delete_key_value(int key)
-{
-
-}
-
-void
-PyThread_ReInitTLS(void)
-{
-
-}
-
-#endif