honor MANUALLY_ADDED_DEPENDENCIES for unity targets

CMake/cotire.cmake

@@ -3456,6 +3456,11 @@ function (cotire_target_link_libraries _target)
 					message (STATUS "unity target ${_unityTargetName} interface link libraries: ${_unityLinkInterfaceLibraries}")
 				endif()
 			endif()
+			get_target_property(_manualDependencies ${_target} MANUALLY_ADDED_DEPENDENCIES)
+			if (_manualDependencies)
+				cotire_map_libraries("${_linkLibrariesStrategy}" _unityManualDependencies ${_manualDependencies})
+				add_dependencies("${_unityTargetName}" _unityManualDependencies)
+			endif()
 		endif()
 	endif()
 endfunction(cotire_target_link_libraries)