* dcrt0.cc (dll_crt0_1): Initialize mainthread stuff here before anything needs

it.
* sigproc.cc (sigproc_init): Move mainthread initialization out of here.
* sigproc.h (sigthread): Add init() method.
(sigframe): Don't try to initialize muto.
* sync.cc: Undef WaitForSingleObject to avoid recursion.

winsup/cygwin/sigproc.h

@@ -40,6 +40,11 @@ struct sigthread
   DWORD frame;
   muto *lock;
   sigthread () : id (0), frame (0), lock (0) {}
+  void init (const char *s)
+  {
+    lock = new_muto (FALSE, s);
+    id = GetCurrentThreadId ();
+  }
 };
 
 class sigframe
@@ -50,8 +55,6 @@ private:
 public:
   void set (sigthread &t, int up = 1)
   {
-    if (!t.lock)
-      t.lock = new_muto (FALSE, "sigthread");
     t.lock->acquire ();
     st = &t;
     t.frame = (DWORD) (up ? __builtin_frame_address (1) :