Simplify thread initialization and GC

* src/lisp.h (PVECHEADERSIZE): New macro.
(XSETPVECTYPESIZE): Use it.
* src/search.c (syms_of_search): No need to initialize or
staticpro last_thing_searched or saved_last_thing_searched, as
the thread code arranges for initialization and GC.
* src/thread.c (main_thread): Initialize statically.
(Fmake_mutex, Fmake_condition_variable, Fmake_thread):
Use ALLOCATE_ZEROED_PSEUDOVECTOR rather than zeroing by hand.
(mark_one_thread): No need to mark Lisp_Object members.
(init_main_thread, init_threads_once): Remove.  All uses removed.

1 files changed, 0 insertions, 1 deletions

diff --git a/src/thread.h b/src/thread.h
index 0514669a87d..498b9909c9f 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -287,7 +287,6 @@ extern void finalize_one_mutex (struct Lisp_Mutex *);
 extern void finalize_one_condvar (struct Lisp_CondVar *);
 extern void maybe_reacquire_global_lock (void);
 
-extern void init_threads_once (void);
 extern void init_threads (void);
 extern void syms_of_threads (void);
 extern bool main_thread_p (const void *);