Added a counter of the total number of existing objects

It may simplify the control of the garbage collector.

lgc.c

@@ -259,6 +259,7 @@ GCObject *luaC_newobjdt (lua_State *L, int tt, size_t sz, size_t offset) {
   global_State *g = G(L);
   char *p = cast_charp(luaM_newobject(L, novariant(tt), sz));
   GCObject *o = cast(GCObject *, p + offset);
+  g->totalobjs++;
   o->marked = luaC_white(g);
   o->tt = tt;
   o->next = g->allgc;
@@ -768,6 +769,7 @@ static void freeupval (lua_State *L, UpVal *uv) {
 
 
 static void freeobj (lua_State *L, GCObject *o) {
+  G(L)->totalobjs--;
   switch (o->tt) {
     case LUA_VPROTO:
       luaF_freeproto(L, gco2p(o));

lstate.c

@@ -279,6 +279,7 @@ static void close_state (lua_State *L) {
   luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size);
   freestack(L);
   lua_assert(gettotalbytes(g) == sizeof(LG));
+  lua_assert(g->totalobjs == 1);
   (*g->frealloc)(g->ud, fromstate(L), sizeof(LG), 0);  /* free main block */
 }
 
@@ -387,6 +388,7 @@ LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
   g->weak = g->ephemeron = g->allweak = NULL;
   g->twups = NULL;
   g->totalbytes = sizeof(LG);
+  g->totalobjs = 1;
   g->GCdebt = 0;
   g->lastatomic = 0;
   setivalue(&g->nilvalue, 0);  /* to signal that state is not yet built */

lstate.h

@@ -250,6 +250,7 @@ typedef struct global_State {
   lua_Alloc frealloc;  /* function to reallocate memory */
   void *ud;         /* auxiliary data to 'frealloc' */
   l_mem totalbytes;  /* number of bytes currently allocated - GCdebt */
+  l_mem totalobjs;  /* total number of objects allocated */
   l_mem GCdebt;  /* bytes allocated not yet compensated by the collector */
   lu_mem GCestimate;  /* an estimate of the non-garbage memory in use */
   lu_mem lastatomic;  /* see function 'genstep' in file 'lgc.c' */