* include/cygwin/version.h: Bump DLL minor number to 8.

* cygmalloc.h: Make more concessions to attempts to get debugging malloc
working.
* debug.h: Ditto.
* dlmalloc.cc: Ditto.
* dlmalloc.h: Ditto.
* malloc_wrapper.cc: Ditto.
* perthread.h (perthread::create): Use calloc to ensure zeroed memory.

winsup/cygwin/perthread.h

@@ -28,8 +28,7 @@ public:
   virtual void set (int n) {TlsSetValue (get_tls (), (void *)n);}
   virtual void *create ()
   {
-    void *s = new char [size ()];
-    memset (s, 0, size ());
+    void *s = calloc (1, size ());
     set (s);
     return s;
   }