Possible build configurations

[Stefan Monnier]

Is it currently possible to have

    (featurep 'xinput2)

or

    (featurep 'x)

be true at the same time as

    (or (featurep 'w32-win) (featurep 'ns-win)
        (featurep 'haiku-win) (featurep 'pgtk-win)
        (featurep 'android-win))

?

According to my reading of the code, the answer is no: these features
are all defined in their respective `<GUI>term.c` or `<GUI>fns.c` and
the current `configure.ac` (and I think current C code) supports only
a single <GUI> active at the same time.

Can someone confirm this?


        Stefan