Fix small matters and improve sysconf()

- Fix mkdeps.com out of memory error
- Remove static memory from __get_cpu_count()
- Add support for passing hyphen to cat in cocmd
- Change more ZipOS errors from ENOTSUP to EROFS
- Specify mem_unit in sysinfo() output on BSD OSes

tool/net/lfuncs.c

@@ -131,7 +131,7 @@ int LuaGetCpuCore(lua_State *L) {
 }
 
 int LuaGetCpuCount(lua_State *L) {
-  lua_pushinteger(L, _getcpucount());
+  lua_pushinteger(L, __get_cpu_count());
   return 1;
 }