configure, meson: move membarrier test to meson

The test is a bit different from the others, in that it does not run
if $membarrier is empty.  For meson, the default can simply be disabled;
if one day we will toggle the default, no change is needed in meson.build.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
5 files changed