Core: Fix qbs build.

Change-Id: I2372ffc07a101110c9c3016c7d18b9d182312954
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>

src/plugins/coreplugin/coreplugin.qbs

@@ -143,6 +143,7 @@ QtcPlugin {
             "editorarea.cpp", "editorarea.h",
             "editormanager.cpp", "editormanager.h", "editormanager_p.h",
             "editorview.cpp", "editorview.h",
+            "editorwindow.cpp", "editorwindow.h",
             "ieditor.cpp", "ieditor.h",
             "ieditorfactory.cpp", "ieditorfactory.h",
             "iexternaleditor.cpp", "iexternaleditor.h",