Bug fix/clang-tidy-performance (#300)

Various clang-tidy-performance fixes:
* noexcept
* performance-noexcept-swap
* performance
* performance-move-const-arg
* performance-unnecessary-value-param
* performance-inefficient-vector-operation
* performance-no-int-to-ptr
* add performance
* performance-inefficient-string-concatenation
* clang-analyzer-deadcode.DeadStores
* performance-inefficient-vector-operation
* clang-analyzer-core.NullDereference
* clang-analyzer-core.UndefinedBinaryOperatorResult
* clang-analyzer-core.CallAndMessage

---------

Co-authored-by: gtsoul-tech <gtsoulkanakis@gmail.com>

tools/hsdump/main.cpp

@@ -337,7 +337,9 @@ void clearDir(const string &path) {
         if (name == "." || name == "..") {
             continue;
         }
-        string f = path + '/' + name;
+        string f = path;
+        f += '/';
+        f += name;
         if (unlink(f.c_str()) < 0) {
             printf("ERROR: couldn't remove file %s: %s\n", f.c_str(),
                    strerror(errno));