Fix: terraform limit acted random when maxing out per_64k_frames setting

uint32 + uint32 can overflow, so cast it to uint64 first.

src/company_cmd.cpp

@@ -266,9 +266,9 @@ void SubtractMoneyFromCompanyFract(CompanyID company, const CommandCost &cst)
 void UpdateLandscapingLimits()
 {
 	for (Company *c : Company::Iterate()) {
-		c->terraform_limit = std::min<uint32>(c->terraform_limit + _settings_game.construction.terraform_per_64k_frames, (uint32)_settings_game.construction.terraform_frame_burst << 16);
-		c->clear_limit     = std::min<uint32>(c->clear_limit     + _settings_game.construction.clear_per_64k_frames,     (uint32)_settings_game.construction.clear_frame_burst << 16);
-		c->tree_limit      = std::min<uint32>(c->tree_limit      + _settings_game.construction.tree_per_64k_frames,      (uint32)_settings_game.construction.tree_frame_burst << 16);
+		c->terraform_limit = std::min<uint64>((uint64)c->terraform_limit + _settings_game.construction.terraform_per_64k_frames, (uint64)_settings_game.construction.terraform_frame_burst << 16);
+		c->clear_limit     = std::min<uint64>((uint64)c->clear_limit     + _settings_game.construction.clear_per_64k_frames,     (uint64)_settings_game.construction.clear_frame_burst << 16);
+		c->tree_limit      = std::min<uint64>((uint64)c->tree_limit      + _settings_game.construction.tree_per_64k_frames,      (uint64)_settings_game.construction.tree_frame_burst << 16);
 	}
 }