535203075e Avoid using numeric_limits for sequence numbers and lock times (Russell Yanofsky)
bafb921507 Remove duplicated code (Hennadii Stepanov)
e4dc39b3bc Replace platform dependent type with proper const (Hennadii Stepanov)
Pull request description:
Switches to named constants, because numeric_limits calls can be harder to read and less portable.
Change was suggested by jamesob in https://github.com/bitcoin/bitcoin/pull/10973#discussion_r213473620
There are no changes in behavior except on some platforms we don't support (ILP64, IP16L32, I16LP32), where `SignalsOptInRBF` and `MutateTxAddInput` functions would now work correctly.
Tree-SHA512: 3f5c6393c260551f65a0edfba55ef7eb3625232eec8d85b1457f26e144aa0b90c7ef5f44b2fd2f7d9be3c3bcb301030a9f5473c21b3bac566cc59b8c8780737c