Add simple runtime benchmarks

For now we add just two binaries, one with assertions taking the
fast path, one with assertions taking the slow path, and the ability
to run 1 of `REQUIRE(true)`, `REQUIRE_NOTHROW`, `REQUIRE_THROWS`
in a loop.

I also split off a CMake preset which enables more tests than the
basic `simple-tests` preset, but does not enable the most expensive
tests which force recompilation of Catch2 multiple times.

benchmarks/assertion_listener.cpp

@@ -0,0 +1,28 @@
+
+//              Copyright Catch2 Authors
+// Distributed under the Boost Software License, Version 1.0.
+//   (See accompanying file LICENSE.txt or copy at
+//        https://www.boost.org/LICENSE_1_0.txt)
+
+// SPDX-License-Identifier: BSL-1.0
+
+#include <catch2/reporters/catch_reporter_event_listener.hpp>
+#include <catch2/reporters/catch_reporter_registrars.hpp>
+
+/**
+ * Event listener that listens to all assertions, forcing assertion slow path
+ */
+class AssertionSlowPathListener : public Catch::EventListenerBase {
+public:
+    static std::string getDescription() {
+        return "Validates ordering of Catch2's listener events";
+    }
+
+    AssertionSlowPathListener(Catch::IConfig const* config) :
+        EventListenerBase(config) {
+        m_preferences.shouldReportAllAssertions = true;
+        m_preferences.shouldReportAllAssertionStarts = true;
+    }
+};
+
+CATCH_REGISTER_LISTENER( AssertionSlowPathListener )