Merge #13691: Remove redundant variables, statements and forward declarations

3dee4cc509 Remove redundant statement (practicalswift)
99be644966 Remove redundant unused variables (practicalswift)
66ed242343 Remove redundant forward declaration (practicalswift)

Pull request description:

  Remove redundant …
  * ~access modifiers,~
  * forward declarations,
  * unused variables,
  * statements, and
  * ~return types from lambdas.~

Tree-SHA512: 328bb7d9c45398e44ecbee32095b6376879470dfddbc2180e037620d8390d524b51d7fda112fd58a078715e04432b24dd6998a2459f3550aa0498aa68de866d4

src/test/miner_tests.cpp

@@ -209,7 +209,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
     const CChainParams& chainparams = *chainParams;
     CScript scriptPubKey = CScript() << ParseHex("04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f") << OP_CHECKSIG;
     std::unique_ptr<CBlockTemplate> pblocktemplate;
-    CMutableTransaction tx,tx2;
+    CMutableTransaction tx;
     CScript script;
     uint256 hash;
     TestMemPoolEntryHelper entry;

src/test/transaction_tests.cpp

@@ -547,7 +547,6 @@ BOOST_AUTO_TEST_CASE(test_witness)
 
     CTransactionRef output1, output2;
     CMutableTransaction input1, input2;
-    SignatureData sigdata;
 
     // Normal pay-to-compressed-pubkey.
     CreateCreditAndSpend(keystore, scriptPubkey1, output1, input1);