gnu: pugixml is a regular input.

* gnu/packages/emulators.scm (mame)[native-inputs]: Move PUGIXML ...
[inputs]: ... here.
* gnu/packages/ftp.scm (filezilla)[native-inputs, inputs]: Likewise.

gnu/packages/emulators.scm

@@ -1339,7 +1339,6 @@ play them on systems for which they were never designed!")
                #t))))))
     (native-inputs
      `(("pkg-config" ,pkg-config)
-       ("pugixml" ,pugixml)
        ("python-sphinx" ,python-sphinx)
        ("texinfo" ,texinfo)))
     (inputs
@@ -1354,6 +1353,7 @@ play them on systems for which they were never designed!")
        ("lua" ,lua)
        ("portaudio" ,portaudio)
        ("portmidi" ,portmidi)
+       ("pugixml" ,pugixml)
        ("python-wrapper" ,python-wrapper)
        ("qtbase" ,qtbase)
        ("rapidjson" ,rapidjson)

gnu/packages/ftp.scm

@@ -224,7 +224,6 @@ output.
     (native-inputs
      `(("gettext" ,gettext-minimal)
        ("pkg-config" ,pkg-config)
-       ("pugixml" ,pugixml)
        ("xdg-utils" ,xdg-utils)))
     (inputs
      `(("dbus" ,dbus)
@@ -233,6 +232,7 @@ output.
        ("libfilezilla" ,libfilezilla)
        ("libidn" ,libidn)
        ("nettle" ,nettle)
+       ("pugixml" ,pugixml)
        ("sqlite" ,sqlite)
        ("wxwidgets" ,wxwidgets)))
     (home-page "https://filezilla-project.org")