Refactor some swift only logic to be re-used by other languages

The logic in AddSwiftInterfaceIncludeDirectories is something
that other languages will want going forward

Source/cmGeneratorTarget.cxx

@@ -1333,18 +1333,18 @@ std::string cmGeneratorTarget::EvaluateInterfaceProperty(
 }
 
 namespace {
-std::string AddSwiftInterfaceIncludeDirectories(
+
+std::string AddLangSpecificInterfaceIncludeDirectories(
   const cmGeneratorTarget* root, const cmGeneratorTarget* target,
-  const std::string& config, cmGeneratorExpressionDAGChecker* context)
+  const std::string& lang, const std::string& config,
+  const std::string& propertyName, cmGeneratorExpressionDAGChecker* context)
 {
   cmGeneratorExpressionDAGChecker dag{ target->GetBacktrace(), target,
-                                       "Swift_MODULE_DIRECTORY", nullptr,
-                                       context };
+                                       propertyName, nullptr, context };
   switch (dag.Check()) {
     case cmGeneratorExpressionDAGChecker::SELF_REFERENCE:
-      dag.ReportError(nullptr,
-                      "$<TARGET_PROPERTY:" + target->GetName() +
-                        ",Swift_MODULE_DIRECTORY>");
+      dag.ReportError(
+        nullptr, "$<TARGET_PROPERTY:" + target->GetName() + ",propertyName");
       CM_FALLTHROUGH;
     case cmGeneratorExpressionDAGChecker::CYCLIC_REFERENCE:
       // No error. We just skip cyclic references.
@@ -1360,13 +1360,11 @@ std::string AddSwiftInterfaceIncludeDirectories(
         target->GetLinkInterfaceLibraries(config, root, true)) {
     for (const cmLinkItem& library : interface->Libraries) {
       if (const cmGeneratorTarget* dependency = library.Target) {
-        if (cm::contains(dependency->GetAllConfigCompileLanguages(),
-                         "Swift")) {
-          std::string value =
-            dependency->GetSafeProperty("Swift_MODULE_DIRECTORY");
+        if (cm::contains(dependency->GetAllConfigCompileLanguages(), lang)) {
+          auto* lg = dependency->GetLocalGenerator();
+          std::string value = dependency->GetSafeProperty(propertyName);
           if (value.empty()) {
-            value =
-              dependency->GetLocalGenerator()->GetCurrentBinaryDirectory();
+            value = lg->GetCurrentBinaryDirectory();
           }
 
           if (!directories.empty()) {
@@ -1380,35 +1378,33 @@ std::string AddSwiftInterfaceIncludeDirectories(
   return directories;
 }
 
-void AddSwiftImplicitIncludeDirectories(
-  const cmGeneratorTarget* target, const std::string& config,
+void AddLangSpecificImplicitIncludeDirectories(
+  const cmGeneratorTarget* target, const std::string& lang,
+  const std::string& config, const std::string& propertyName,
   EvaluatedTargetPropertyEntries& entries)
 {
   if (const auto* libraries = target->GetLinkImplementationLibraries(config)) {
     cmGeneratorExpressionDAGChecker dag{ target->GetBacktrace(), target,
-                                         "Swift_MODULE_DIRECTORY", nullptr,
-                                         nullptr };
+                                         propertyName, nullptr, nullptr };
 
     for (const cmLinkImplItem& library : libraries->Libraries) {
       if (const cmGeneratorTarget* dependency = library.Target) {
         if (!dependency->IsInBuildSystem()) {
           continue;
         }
-        if (cm::contains(dependency->GetAllConfigCompileLanguages(),
-                         "Swift")) {
+        if (cm::contains(dependency->GetAllConfigCompileLanguages(), lang)) {
+          auto* lg = dependency->GetLocalGenerator();
           EvaluatedTargetPropertyEntry entry{ library, library.Backtrace };
 
-          if (cmProp val = dependency->GetProperty("Swift_MODULE_DIRECTORY")) {
+          if (cmProp val = dependency->GetProperty(propertyName)) {
             entry.Values.emplace_back(*val);
           } else {
-            entry.Values.emplace_back(
-              dependency->GetLocalGenerator()->GetCurrentBinaryDirectory());
+            entry.Values.emplace_back(lg->GetCurrentBinaryDirectory());
           }
 
-          cmExpandList(AddSwiftInterfaceIncludeDirectories(target, dependency,
-                                                           config, &dag),
+          cmExpandList(AddLangSpecificInterfaceIncludeDirectories(
+                         target, dependency, lang, config, propertyName, &dag),
                        entry.Values);
-
           entries.Entries.emplace_back(std::move(entry));
         }
       }
@@ -3442,7 +3438,8 @@ std::vector<BT<std::string>> cmGeneratorTarget::GetIncludeDirectories(
     this, config, lang, &dagChecker, this->IncludeDirectoriesEntries);
 
   if (lang == "Swift") {
-    AddSwiftImplicitIncludeDirectories(this, config, entries);
+    AddLangSpecificImplicitIncludeDirectories(
+      this, lang, config, "Swift_MODULE_DIRECTORY", entries);
   }
 
   AddInterfaceEntries(this, config, "INTERFACE_INCLUDE_DIRECTORIES", lang,