Codechange: Use .fill() to clear an array instead of assigning a new array. (#13880)

Avoids allocating a temporary on the stack.

src/company_cmd.cpp

@@ -787,7 +787,7 @@ static IntervalTimer<TimerGameEconomy> _economy_companies_yearly({TimerGameEcono
 	for (Company *c : Company::Iterate()) {
 		/* Move expenses to previous years. */
 		std::rotate(std::rbegin(c->yearly_expenses), std::rbegin(c->yearly_expenses) + 1, std::rend(c->yearly_expenses));
-		c->yearly_expenses[0] = {};
+		c->yearly_expenses[0].fill(0);
 		InvalidateWindowData(WC_FINANCES, c->index);
 	}