Move dependencies in 'external' directory and pdate git submodules

external/Catch2/tests/ExtraTests/X91-AmalgamatedCatch.cpp

@@ -0,0 +1,38 @@
+
+//              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
+
+/**\file
+ * This file serves as a simple compilation test against the amalgamated
+ * version of Catch2.
+ */
+
+#include "catch_amalgamated.hpp"
+
+TEST_CASE("Just a dummy test") {
+    auto i = GENERATE(1, 2, 3);
+    SECTION("a") {
+        REQUIRE(i != 4);
+    }
+    SECTION("b") {
+        CHECK(i != 5);
+    }
+    REQUIRE_THAT(1,
+                 Catch::Matchers::Predicate<int>([](int i) {
+                     return i % 2 == 1;
+                 }));
+}
+
+TEMPLATE_TEST_CASE("Trivial template test case", "", char, short) {
+    STATIC_REQUIRE(sizeof(TestType) <= sizeof(int));
+}
+
+TEST_CASE("Benchmark test", "[!benchmark]") {
+    BENCHMARK("Allocation benchmark") {
+        return std::vector<int>(10);
+    };
+}