revert pull 101 because it causes seg fault in stress.d

src/gc/gcx.d

@@ -2014,54 +2014,26 @@ struct Gcx
     void minimize()
     {
         debug(PRINTF) printf("Minimizing.\n");
+        size_t n;
+        size_t pn;
+        Pool*  pool;
+        size_t ncommitted;
 
-        static bool isUsed(Pool *pool)
-        {
-            return pool.freepages < pool.npages;
-        }
-
-        // semi-stable partition
-        for (size_t i = 0; i < npools; ++i)
-        {
-            auto pool = pooltable[i];
-            // find first unused pool
-            if (isUsed(pool)) continue;
-
-            // move used pools before unused ones
-            size_t j = i + 1;
-            for (; j < npools; ++j)
-            {
-                pool = pooltable[j];
-                if (!isUsed(pool)) continue;
-                // swap
-                pooltable[j] = pooltable[i];
-                pooltable[i] = pool;
-                ++i;
-            }
-            // npooltable[0     .. i]      => used
-            // npooltable[i + 1 .. npools] => free
-
-            // free unused pools
-            for (j = i + 1; j < npools; ++j)
-            {
-                pool = pooltable[j];
-                debug(PRINTF) printFreeInfo(pool);
-                pool.Dtor();
-                cstdlib.free(pool);
-            }
-            npools = i + 1;
-        }
-
-        if (npools)
-        {
-            minAddr = pooltable[0].baseAddr;
-            maxAddr = pooltable[npools - 1].topAddr;
-        }
-        else
+        Outer:
+        for (n = 0; n < npools; n++)
         {
-            minAddr = maxAddr = null;
+            pool = pooltable[n];
+            debug(PRINTF) printFreeInfo(pool);
+            if(pool.freepages < pool.npages) continue;
+            pool.Dtor();
+            cstdlib.free(pool);
+            memmove(pooltable + n,
+                    pooltable + n + 1,
+                    (--npools - n) * (Pool*).sizeof);
+            n--;
         }
-
+        minAddr = pooltable[0].baseAddr;
+        maxAddr = pooltable[npools - 1].topAddr;
         debug(PRINTF) printf("Done minimizing.\n");
     }