Ninja Multi-Config: Restore rebuild_cache and edit_cache targets

Since commit dcf9f4d2f7 (Ninja Multi-Config: Add support for
cross-config custom commands, 2020-12-09) we were not generating these
targets.  Restore them and add a test.

Fixes: #21722

Source/cmNinjaUtilityTargetGenerator.cxx

@@ -35,6 +35,11 @@ cmNinjaUtilityTargetGenerator::~cmNinjaUtilityTargetGenerator() = default;
 
 void cmNinjaUtilityTargetGenerator::Generate(const std::string& config)
 {
+  if (!this->GetGeneratorTarget()->Target->IsPerConfig()) {
+    this->WriteUtilBuildStatements(config, config);
+    return;
+  }
+
   for (auto const& fileConfig : this->GetConfigNames()) {
     if (!this->GetGlobalGenerator()
            ->GetCrossConfigs(fileConfig)

Tests/RunCMake/NinjaMultiConfig/RunCMakeTest.cmake

@@ -85,6 +85,9 @@ set(RunCMake_TEST_OPTIONS "-DCMAKE_CONFIGURATION_TYPES=RelWithDebInfo\\;Debug\\;
 run_cmake_configure(Simple)
 unset(RunCMake_TEST_OPTIONS)
 include(${RunCMake_TEST_BINARY_DIR}/target_files.cmake)
+run_ninja(Simple targets-default build.ninja -t targets)
+run_ninja(Simple targets-debug build-Debug.ninja -t targets)
+run_ninja(Simple targets-release build-Debug.ninja -t targets)
 run_cmake_build(Simple debug-target Debug simpleexe)
 run_ninja(Simple debug-target build-Debug.ninja simplestatic)
 get_filename_component(simpleshared_Release "${TARGET_FILE_simpleshared_Release}" NAME)

Tests/RunCMake/NinjaMultiConfig/Simple-targets-debug-ninja-stdout.txt

@@ -0,0 +1,3 @@
+(rebuild_cache: phony.*
+edit_cache: phony|edit_cache: phony.*
+rebuild_cache: phony)

Tests/RunCMake/NinjaMultiConfig/Simple-targets-default-ninja-stdout.txt

@@ -0,0 +1,3 @@
+(rebuild_cache: phony.*
+edit_cache: phony|edit_cache: phony.*
+rebuild_cache: phony)

Tests/RunCMake/NinjaMultiConfig/Simple-targets-release-ninja-stdout.txt

@@ -0,0 +1,3 @@
+(rebuild_cache: phony.*
+edit_cache: phony|edit_cache: phony.*
+rebuild_cache: phony)