QA: Add pcbnew unit tests CMake subdir

Also modify the linkage of kiface objects, as this is not
supported by older CMake versions.

This was accidentally removed with the reversion of the application
of the wrong patch (8f11a2133).

QA: fix object files

qa/CMakeLists.txt

@@ -12,13 +12,18 @@ if( KICAD_SCRIPTING_MODULES )
 
 endif()
 
-# common QA helpers
+# Shared QA helper libraries
 add_subdirectory( qa_utils )
 add_subdirectory( unit_test_utils )
 
+# Unit tests
 add_subdirectory( common )
+add_subdirectory( pcbnew )
 add_subdirectory( shape_poly_set_refactor )
+
+# Utility/test programs
 add_subdirectory( pcb_parse_input )
+
 # add_subdirectory( pcb_test_window )
 # add_subdirectory( polygon_triangulation )
 # add_subdirectory( polygon_generator )

qa/pcbnew/CMakeLists.txt

@@ -36,6 +36,10 @@ add_executable( qa_pcbnew
 
     test_graphics_import_mgr.cpp
     test_pad_naming.cpp
+
+    # Older CMakes cannot link OBJECT libraries
+    # https://cmake.org/pipermail/cmake/2013-November/056263.html
+    $<TARGET_OBJECTS:pcbnew_kiface_objects>
 )
 
 if( BUILD_GITHUB_PLUGIN )
@@ -73,7 +77,6 @@ target_link_libraries( qa_pcbnew
     qa_utils
     lib_dxf
     idf3
-    pcbnew_kiface_objects
     unit_test_utils
     ${wxWidgets_LIBRARIES}
     ${GITHUB_PLUGIN_LIBRARIES}