consensus: make COIN & MAX_MONEY constexpr

Author: fanquake

src/consensus/amount.h

@@ -11,7 +11,7 @@
 /** Amount in satoshis (Can be negative) */
 typedef int64_t CAmount;
 
-static const CAmount COIN = 100000000;
+static constexpr CAmount COIN = 100000000;
 
 /** No amount larger than this (in satoshi) is valid.
  *
@@ -22,7 +22,7 @@ static const CAmount COIN = 100000000;
  * critical; in unusual circumstances like a(nother) overflow bug that allowed
  * for the creation of coins out of thin air modification could lead to a fork.
  * */
-static const CAmount MAX_MONEY = 21000000 * COIN;
+static constexpr CAmount MAX_MONEY = 21000000 * COIN;
 inline bool MoneyRange(const CAmount& nValue) { return (nValue >= 0 && nValue <= MAX_MONEY); }
 
 #endif //  BITCOIN_CONSENSUS_AMOUNT_H