Ensure no thruption is delivered until restarts are available.

Borrow appropriate check from David Lichteblau's commit in mainline.

* src/compiler/generic/parms.lisp (*common-static-symbols*): added *restart-clusters*
* src/runtime/thread.c (create_thread_struct): bind *restart-clusters*
(thread_may_interrupt): check *restart-clusters*

src/compiler/generic/parms.lisp

@@ -81,6 +81,7 @@
     sb!unix::*allow-with-interrupts*
     sb!unix::*interrupts-enabled*
     sb!unix::*interrupt-pending*
+    #!+sb-thruption sb!impl::*restart-clusters*
     *in-without-gcing*
     *gc-inhibit*
     *gc-pending*

src/runtime/thread.c

@@ -875,6 +875,7 @@ create_thread_struct(lispobj initial_function) {
 #if defined(LISP_FEATURE_WIN32) && defined(LISP_FEATURE_SB_THREAD)
     bind_variable(GC_SAFE,NIL,th);
     bind_variable(IN_SAFEPOINT,NIL,th);
+    bind_variable(RESTART_CLUSTERS,NIL,th);
     bind_variable(DISABLE_SAFEPOINTS,NIL,th);
 #endif
 
@@ -1068,6 +1069,14 @@ static inline int thread_may_interrupt()
   // 2) INTERRUPTS_ENABLED is not-nil
   // 3) !pseudo_atomic (now guaranteed by safepoint-related callers)
 
+  // borrowed from David Lichteblau's commit in main branch
+  if (SymbolValue(RESTART_CLUSTERS, self) == NIL)
+      /* This special case prevents TERMINATE-THREAD from hitting
+       * during INITIAL-THREAD-FUNCTION before it's ready.  Curiously,
+       * deferrables are already unblocked there.  Further
+       * investigation may be in order. */
+      return 0;
+
   if (SymbolValue(INTERRUPTS_ENABLED, self) == NIL)
       return 0;