cond test: Don't make assumptions about struct sigaction member order
cond test: Don't make assumptions about struct sigaction member order

On x86 (and apparently most other Linux architectures), the union
with the signal handler is the first member, but on MIPS Linux,
the first struct member is sa_flags (possibly done to be compatible
with IRIX). Zero out the struct and fill in the field we want by name.

Signed-off-by: Simon McVittie <0e1aea601907c1a85c2dc96e5ea37e23c58d2e9b@collabora.com>

endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib