Meson 0.58.2 does not need b_staticpic=$pie anymore, and has
stabilized the keyval module. Remove the workaround and use a few
replacements for features deprecated in the 0.57.0 release cycle.
One feature that we would like to use is passing dependencies to
summary. However, that was broken in 0.59.0 and 0.59.1. Therefore,
use the embedded Meson if the host has anything older than 0.59.2,
but allow --meson= to use 0.58.2.
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>