Fix clang-tidy performance-inefficient-vector-operation warnings

.clang-tidy

@@ -4,6 +4,7 @@ Checks: [-*,
          performance-enum-size,
          performance-faster-string-find,
          performance-for-range-copy,
+         performance-inefficient-vector-operation,
 
          # Skipping these temporarily because they are very noisy
          -bugprone-narrowing-conversions,

src/broker/Manager.cc

@@ -678,6 +678,7 @@ void Manager::DoTerminate() {
     iosource_mgr->UnregisterFd(bstate->loggerQueue->FlareFd(), this);
 
     vector<string> stores_to_close;
+    stores_to_close.reserve(data_stores.size());
 
     for ( auto& x : data_stores )
         stores_to_close.push_back(x.first);

src/script_opt/Stmt.cc

@@ -1056,6 +1056,8 @@ StmtPtr InitStmt::Duplicate() {
     // Need to duplicate the initializer list since later reductions
     // can modify it in place.
     std::vector<IDPtr> new_inits;
+    new_inits.reserve(inits.size());
+
     for ( const auto& id : inits )
         new_inits.push_back(id);
 

src/zeek-setup.cc

@@ -942,6 +942,7 @@ SetupResult setup(int argc, char** argv, Options* zopts) {
     }
 
     std::vector<SignatureFile> all_signature_files;
+    all_signature_files.reserve(options.signature_files.size() + zeek::detail::sig_files.size());
 
     // Append signature files given on the command line
     for ( const auto& sf : options.signature_files )