Broadening the use of branch hints

More uses of macros 'likely'/'unlikely' (renamed to
'l_likely'/'l_unlikely'), both in range (extended to the
libraries) and in scope (extended to hooks, stack growth).

lgc.c

@@ -916,7 +916,7 @@ static void GCTM (lua_State *L) {
     L->ci->callstatus &= ~CIST_FIN;  /* not running a finalizer anymore */
     L->allowhook = oldah;  /* restore hooks */
     g->gcrunning = running;  /* restore state */
-    if (unlikely(status != LUA_OK)) {  /* error while running __gc? */
+    if (l_unlikely(status != LUA_OK)) {  /* error while running __gc? */
       luaE_warnerror(L, "__gc metamethod");
       L->top--;  /* pops error object */
     }