Merge #19935: Move SaltedHashers to separate file and add some new ones

281fd1a4a032cded7f9ea9857e3e99fc793c714b Replace KeyIDHasher with SaltedSipHasher (Andrew Chow)
210b693db66e7c5b618014b5a287aee15af00045 Add generic SaltedSipHasher (Andrew Chow)
95e61c1cf2a91d041c8025306ba36f0ea2806894 Move Hashers to util/hasher.{cpp/h} (Andrew Chow)

Pull request description:

  There are existing `SaltedOutPointHasher` and `SaltedTxidHasher` classes used for `std::unordered_map` and `std::unordered_set` that could be useful in other places in the codebase. So we these to their own `saltedhash.{cpp/h}` file. An existing `KeyIDHasher` is moved there too. Additionally, `ScriptIDHasher`, `SaltedPubkeyHasher`, and `SaltedScriptHasher` are added so that they can be used in future work.

  `KeyIDHasher` and `ScriptIDHasher` are not salted so that equality comparisons of maps and sets keyed by `CKeyID` and `CScriptID` will actually work.

  Split from #19602 (and a few other PRs/branches I have).

ACKs for top commit:
  laanwj:
    Code review ACK 281fd1a4a032cded7f9ea9857e3e99fc793c714b
  jonatack:
    ACK 281fd1a4a032cded7f9ea9857e3e99fc793c714b, code review, debug build and ran bitcoind after rebasing to master @ dff0f6f753ea
  fjahr:
    utACK 281fd1a4a032cded7f9ea9857e3e99fc793c714b

Tree-SHA512: bb03b231ccf3c9ecefc997b8da9c3770af4819f9be5b0a72997a103864e84046a2ac39b8eadf0dc9247bdccd53f86f433642e3a098882e6748341a9e7736271b

1 files changed, 0 insertions, 2 deletions

diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index d18182c07d..9ae7b921b3 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -1127,5 +1127,3 @@ CTxMemPool::EpochGuard::~EpochGuard()
     ++pool.m_epoch;
     pool.m_has_epoch_guard = false;
 }
-
-SaltedTxidHasher::SaltedTxidHasher() : k0(GetRand(std::numeric_limits<uint64_t>::max())), k1(GetRand(std::numeric_limits<uint64_t>::max())) {}