Integrate Nonius benchmark into Catch2

Changes done to Nonius:
* Moved things into "Catch::Benchmark" namespace
* Benchmarks were integrated with `TEST_CASE`/`SECTION`/`GENERATE` macros
* Removed Nonius's parameters for benchmarks, Generators should be used instead
* Added relevant methods to the reporter interface (default-implemented, to avoid
breaking existing 3rd party reporters)
* Async processing is guarded with `_REENTRANT` macro for GCC/Clang, used by default
on MSVC
* Added a macro `CATCH_CONFIG_DISABLE_BENCHMARKING` that removes all traces of
benchmarking from Catch

projects/SelfTest/IntrospectiveTests/CmdLine.tests.cpp

@@ -462,4 +462,32 @@ TEST_CASE( "Process can be configured on command line", "[config][command-line]"
 #endif
         }
     }
+
+#ifndef CATCH_CONFIG_DISABLE_BENCHMARKING 
+    SECTION("Benchmark options") {
+        SECTION("samples") {
+            CHECK(cli.parse({ "test", "--benchmark-samples=200" }));
+
+            REQUIRE(config.benchmarkSamples == 200);
+        }
+        
+        SECTION("resamples") {
+            CHECK(cli.parse({ "test", "--benchmark-resamples=20000" }));
+
+            REQUIRE(config.benchmarkResamples == 20000);
+        }
+
+        SECTION("resamples") {
+            CHECK(cli.parse({ "test", "--benchmark-confidence-interval=0.99" }));
+
+            REQUIRE(config.benchmarkConfidenceInterval == Catch::Detail::Approx(0.99));
+        }
+
+        SECTION("resamples") {
+            CHECK(cli.parse({ "test", "--benchmark-no-analysis" }));
+
+            REQUIRE(config.benchmarkNoAnalysis);
+        }
+    }
+#endif
 }