Give Catch3 its own build names and headers

Catch2 compatibility means the API tests are written in: the macros, such
as TEST_CASE and REQUIRE, and the Catch:: namespace. It does not mean
Catch2's build names or header paths. find_package(Catch2) found Catch3,
and a project using both frameworks met two packages, two sets of targets,
two Catch.cmake modules and two catch2/ header trees with the same names.

Build names:
- CMake: project and package Catch3, targets Catch3::Catch3 and
  Catch3::Catch3WithMain, libraries Catch3 and Catch3Main, options
  CATCH3_*, lib/cmake/Catch3 with Catch3Config, and pkg-config catch3 and
  catch3-with-main. The version is Catch3's, 0.3.0, compatible within a
  minor version.
- The CMake scripts are Catch3.cmake (catch3_discover_tests),
  Catch3AddTests.cmake and Catch3ShardTests.cmake
  (catch3_add_sharded_tests); the helpers they define at ctest time have a
  catch3_ prefix. ParseAndAddCatchTests.cmake, deprecated upstream, is gone.
- Bazel //:catch3 and //:catch3_main, Meson catch3 and catch3-with-main
  (with override_dependency), Xmake catch3 and catch3_main, Premake Catch3
  and Catch3WithMain. Visual Studio projects get GUIDs of their own.
- The Progmasoft::Catch3 target and package are gone: property testing
  and snapshots are part of Catch3::Catch3. Their sources now build with
  the library's warning flags, so property failures are built field by
  field (no missing initializers) and the default property name is a
  thread-local pointer to the name its scope owns (no global destructor).

Headers: the engine moved from src/catch2 to src/Progmasoft/Catch3 with
Progmasoft names, so <catch2/catch_test_macros.hpp> is
<Progmasoft/Catch3/TestMacros.hpp>, <catch2/matchers/catch_matchers_string.hpp>
is <Progmasoft/Catch3/Matchers/String.hpp>, and interface headers are named
after their interface, such as Interfaces/IConfig.hpp. Include guards
became #pragma once. The installed headers go to include/Progmasoft.
src/Progmasoft/Context.cpp is StrategyContext.cpp, so no two sources share
a file name.

tools/scripts/upstreamFiles.txt lists the files that come from Catch2.
The license check expects BSL-1.0 on them and Progmasoft's header on the
rest of src/Progmasoft; the convenience-header check, the amalgamation
script and the surrogate tests take the engine's headers from it. The
amalgamated files are regenerated. The header-guard workflow checks for
#pragma once instead of checkguard.

Documents, the README and the release notes describe the new names.

1 files changed, 54 insertions, 0 deletions

diff --git a/src/Progmasoft/Catch3/Benchmark/Benchmark.cpp b/src/Progmasoft/Catch3/Benchmark/Benchmark.cpp
new file mode 100644
index 00000000..8967b12c
--- /dev/null
+++ b/src/Progmasoft/Catch3/Benchmark/Benchmark.cpp
@@ -0,0 +1,54 @@
+
+//              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 <Progmasoft/Catch3/Benchmark/Benchmark.hpp>
+
+#include <algorithm>
+#include <chrono>
+#include <cmath>
+
+namespace Catch {
+    namespace Benchmark {
+        namespace Detail {
+
+            Environment measure_environment_default() {
+                return Detail::measure_environment<default_clock>();
+            }
+
+            ExecutionPlan prepare_default( const IConfig& cfg,
+                                           Environment env,
+                                           BenchmarkFunction&& fun ) {
+                // This mirrors Benchmark::prepare<default_clock>(), but with the
+                // clock fixed so it is instantiated once here in the library.
+                auto min_time = env.clock_resolution.mean * Detail::minimum_ticks;
+                auto run_time = std::max(
+                    min_time,
+                    std::chrono::duration_cast<decltype( min_time )>(
+                        cfg.benchmarkWarmupTime() ) );
+                auto&& test = Detail::run_for_at_least<default_clock>(
+                    std::chrono::duration_cast<IDuration>( run_time ), 1, fun );
+                int new_iters = static_cast<int>(
+                    std::ceil( min_time * test.iterations / test.elapsed ) );
+                return { new_iters,
+                         test.elapsed / test.iterations * new_iters *
+                             cfg.benchmarkSamples(),
+                         CATCH_MOVE( fun ),
+                         std::chrono::duration_cast<FDuration>(
+                             cfg.benchmarkWarmupTime() ),
+                         Detail::warmup_iterations };
+            }
+
+            std::vector<FDuration> run_plan_default( ExecutionPlan const& plan,
+                                                     const IConfig& cfg,
+                                                     Environment env ) {
+                return plan.run<default_clock>( cfg, env );
+            }
+
+        } // namespace Detail
+    } // namespace Benchmark
+} // namespace Catch