code review 8454043: runtime: reset dangling typed pointer

src/pkg/runtime/runtime.h

 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 /*
  * basic types
  */
 typedef signed char             int8;
 typedef unsigned char           uint8;
 typedef signed short            int16;
@@ skipping 299 matching lines @@
         uint32  locked; // tracking for LockOSThread
         M*      nextwaitm;      // next M waiting for lock
         uintptr waitsema;       // semaphore for parking on locks
         uint32  waitsemacount;
         uint32  waitsemalock;
         GCStats gcstats;
         bool    racecall;
         bool    needextram;
         void*   racepc;
         void    (*waitunlockf)(Lock*);
-        Lock*   waitlock;
+        void*   waitlock;
         uint32  moreframesize_minalloc;
 
         uintptr settype_buf[1024];
         uintptr settype_bufsize;
 
 #ifdef GOOS_windows
         void*   thread;         // thread handle
 #endif
 #ifdef GOOS_plan9
         int8*           notesig;
@@ skipping 667 matching lines @@
 extern float64 runtime·neginf;
 extern uint64 ·nan;
 extern uint64 ·posinf;
 extern uint64 ·neginf;
 #define ISNAN(f) ((f) != (f))
 
 enum
 {
         UseSpanType = 1,
 };