Add some cpp<->chai performance tests

performance_tests/profile_fun_wrappers.cpp

@@ -0,0 +1,20 @@
+#include <chaiscript/chaiscript.hpp>
+#include <chaiscript/chaiscript_stdlib.hpp>
+
+double f(const std::string &, double, bool) noexcept {
+  return .0;
+}
+
+int main()
+{
+  chaiscript::ChaiScript chai(chaiscript::Std_Lib::library());
+
+  chai.add(chaiscript::fun(&f), "f");
+
+  const auto f = chai.eval<std::function<void ()>>(R"(fun(){ f("str", 1.2, false); })");
+
+  for (int i = 0; i < 100000; ++i) {
+    f();
+  }
+
+}