LINK_OPTIONS: Add new family of properties

This family enable to manage link flags

Three new properties:
* directory property: LINK_OPTIONS
* target properties: LINK_OPTIONS and INTERFACE_LINK_OPTIONS

Two new commands
* add_link_options(): to populate directory property
* target_link_options(): to populate target properties

Fixes: #16543

Source/cmTargetLinkOptionsCommand.h

@@ -0,0 +1,41 @@
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#ifndef cmTargetLinkOptionsCommand_h
+#define cmTargetLinkOptionsCommand_h
+
+#include "cmConfigure.h" // IWYU pragma: keep
+
+#include <string>
+#include <vector>
+
+#include "cmTargetPropCommandBase.h"
+
+class cmCommand;
+class cmExecutionStatus;
+class cmTarget;
+
+class cmTargetLinkOptionsCommand : public cmTargetPropCommandBase
+{
+public:
+  /**
+   * This is a virtual constructor for the command.
+   */
+  cmCommand* Clone() override { return new cmTargetLinkOptionsCommand; }
+
+  /**
+   * This is called when the command is first encountered in
+   * the CMakeLists.txt file.
+   */
+  bool InitialPass(std::vector<std::string> const& args,
+                   cmExecutionStatus& status) override;
+
+private:
+  void HandleMissingTarget(const std::string& name) override;
+
+  bool HandleDirectContent(cmTarget* tgt,
+                           const std::vector<std::string>& content,
+                           bool prepend, bool system) override;
+  std::string Join(const std::vector<std::string>& content) override;
+};
+
+#endif