Fix: Use modern comparisons instead of memcmp in cache check.

This uses C++20 default operator<=> to provide comparisons of some objects.

This works properly with caches that containers.

src/saveload/company_sl.cpp

@@ -96,7 +96,7 @@ CompanyManagerFace ConvertFromOldCompanyManagerFace(uint32_t face)
 void AfterLoadCompanyStats()
 {
 	/* Reset infrastructure statistics to zero. */
-	for (Company *c : Company::Iterate()) MemSetT(&c->infrastructure, 0);
+	for (Company *c : Company::Iterate()) c->infrastructure = {};
 
 	/* Collect airport count. */
 	for (const Station *st : Station::Iterate()) {