Merge #14214: convert C-style (void) parameter lists to C++ style ()

3ccfa34b32 convert C-style (void) parameter lists to C++ style () (Arvid Norberg)

Pull request description:

  In C, an empty parameter list, `()`, means the function takes any arguments, and `(void)` means the function does not take any parameters.
  In C++, an empty parameter list means the function does not take any parameters.

  So, C++ still supports `(void)` parameter lists with the same semantics, why change to `()`?

  1. removing the redundant `void` improves signal-to-noise ratio of the code
  2. using `(void)` exposes a rare inconsistency in that a template taking a template `(T)` parameter list, cannot be instantiated with `T=void`

Tree-SHA512: be2897b6c5e474873aa878ed6bac098382cd21866aec33752fe40b089a6331aa6263cae749aba1b4a41e8467f1a47086d32eb74abaf09927fd5a2f44a4b2109a

src/validation.cpp

@@ -4682,7 +4682,7 @@ int VersionBitsTipStateSinceHeight(const Consensus::Params& params, Consensus::D
 
 static const uint64_t MEMPOOL_DUMP_VERSION = 1;
 
-bool LoadMempool(void)
+bool LoadMempool()
 {
     const CChainParams& chainparams = Params();
     int64_t nExpiryTimeout = gArgs.GetArg("-mempoolexpiry", DEFAULT_MEMPOOL_EXPIRY) * 60 * 60;
@@ -4759,7 +4759,7 @@ bool LoadMempool(void)
     return true;
 }
 
-bool DumpMempool(void)
+bool DumpMempool()
 {
     int64_t start = GetTimeMicros();