Merge bitcoin#28825: fuzz: Minor improvements to tx_package_eval target

6a91791 fuzz: allow fake and duplicate inputs in tx_package_eval target (Greg Sanders)
a0626cc fuzz: allow reaching MempoolAcceptResult::ResultType::DIFFERENT_WITNESS in tx_package_eval target (Greg Sanders)

Pull request description:

  Exercises `DIFFERENT_WITNESS` by using "blank" WSH() and allowing witness to determine wtxid, and attempts to make invalid/duplicate inputs.

ACKs for top commit:
  dergoegge:
    Coverage looks good to me ACK 6a91791

Tree-SHA512: db894f5f5b81c6b454874baf11f296462832285f41ccb09f23c0db92b9abc98f8ecacd72fc8f60dc92cb7947f543a2e55bed2fd210b0e8ca7c7d5389d90b14af

Author: fanquake

src/test/util/script.h

@@ -16,6 +16,18 @@ static const CScript P2SH_OP_TRUE{
     << ToByteVector(CScriptID{CScript{} << OP_TRUE})
     << OP_EQUAL};
 
+static const std::vector<uint8_t> EMPTY{};
+static const CScript P2WSH_EMPTY{
+    CScript{}
+    << OP_0
+    << ToByteVector([] {
+           uint256 hash;
+           CSHA256().Write(EMPTY.data(), EMPTY.size()).Finalize(hash.begin());
+           return hash;
+       }())};
+static const std::vector<std::vector<uint8_t>> P2WSH_EMPTY_TRUE_STACK{{static_cast<uint8_t>(OP_TRUE)}, {}};
+static const std::vector<std::vector<uint8_t>> P2WSH_EMPTY_TWO_STACK{{static_cast<uint8_t>(OP_2)}, {}};
+
 /** Flags that are not forbidden by an assert in script validation */
 bool IsValidFlagCombination(unsigned flags);