meson: merge all cc_flags arrays into one
meson: merge all cc_flags arrays into one

The split of arrays is fairly arbitrary and a hang over from the way we
had to structure lists of flags when we used GNULIB's compiler flag
checking m4 logic.

The separate lists leads to cases where we enable a flag in one list and
have contradictory setting in another list, which leads to confusion.

Reviewed-by: Pavel Hrdina <d4772d05997b8abf035041e3b4f4996380ea7e7a@redhat.com>
Signed-off-by: Daniel P. Berrangé <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>

crobinso/libvirt,zippy2/libvirt,crobinso/libvirt,zippy2/libvirt,libvirt/libvirt,libvirt/libvirt,nertpinx/libvirt,olafhering/libvirt,olafhering/libvirt,jfehlig/libvirt,libvirt/libvirt,libvirt/libvirt,nertpinx/libvirt,olafhering/libvirt,nertpinx/libvirt,jfehlig/libvirt,nertpinx/libvirt,nertpinx/libvirt,crobinso/libvirt,zippy2/libvirt,jfehlig/libvirt,olafhering/libvirt,zippy2/libvirt,jfehlig/libvirt,crobinso/libvirt