Pass on all AM_CPPFLAGS and CPPFLAGS to g-ir-scanner
Pass on all AM_CPPFLAGS and CPPFLAGS to g-ir-scanner

Failure to do so causes a false-positive in Debian's build log checks,
which check that "hardening" flags are passed to all compilations.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=65293
Reviewed-by: Guillaume Desmottes <f16649c7afcd84e3350287183c4ed23cb1aea57c@collabora.co.uk>

Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib