Enable misc-use-anonymous-namespace diagnostic in clang-tidy

.clang-tidy

@@ -18,7 +18,6 @@ Checks: >
   -misc-no-recursion,
   -misc-non-private-member-variables-in-classes,
   -misc-unused-parameters,
-  -misc-use-anonymous-namespace,
   -modernize-avoid-c-arrays,
   -modernize-loop-convert,
   -modernize-use-nodiscard,

1stsamples/stl/main.cpp

@@ -3,7 +3,9 @@
 #include <thread>
 #include <vector>
 
-static void Task(const std::string& msg) { std::cout << "thread number: " + msg << '\n'; }
+namespace {
+void Task(const std::string& msg) { std::cout << "thread number: " + msg << '\n'; }
+}  // namespace
 
 int main() {
   const auto num_max_threads = std::thread::hardware_concurrency();

1stsamples/tbb/main.cpp

@@ -2,7 +2,8 @@
 
 #include <iostream>
 
-static int FibFunc(int n) {
+namespace {
+int FibFunc(int n) {
   if (n < 2) {
     return n;
   }
@@ -14,5 +15,6 @@ static int FibFunc(int n) {
   g.wait();
   return x + y;
 }
+}  // namespace
 
 int main() { return FibFunc(10) - 55; }

tasks/stl/example/src/ops_stl.cpp

@@ -39,9 +39,10 @@ bool nesterov_a_test_task_stl::TestSTLTaskSequential::post_processing_impl() {
   return true;
 }
 
-static std::mutex my_mutex;
+namespace {
+std::mutex my_mutex;
 
-static void AtomOps(std::vector<int> vec, const std::string &ops, std::promise<int> &&pr) {
+void AtomOps(std::vector<int> vec, const std::string &ops, std::promise<int> &&pr) {
   auto sz = vec.size();
   int reduction_elem = 0;
   if (ops == "+") {
@@ -57,6 +58,7 @@ static void AtomOps(std::vector<int> vec, const std::string &ops, std::promise<i
   }
   pr.set_value(reduction_elem);
 }
+}  // namespace
 
 bool nesterov_a_test_task_stl::TestSTLTaskParallel::pre_processing_impl() {
   // Init vectors