Don't attempt to use exec() on the kshortcutsdialog for Emscripten - no longer crashes, but still doesn't work - haven't investigated why yet.
Right - kde's own executables (kde4-config, etc) will cause linker errors due to missing emscripten-qt callbacks (e.g. EMSCRIPTENQT_attemptedLocalEventLoop etc) when used with statically compiled native emscripten-qt libraries - add a dummy implementation for some of these, and auto-link it via KDE4_ADD_EXECUTABLE for kdelib's own executables.
Add -lrt to the linker flags for the native build, for  'clock_gettime'
Link order matters with static, native builds - move QtCore to the end.