Try to avoid apparent platform-dependency in IPC::Run

Try to avoid apparent platform-dependency in IPC::Run

It's hard to believe, but buildfarm results from the new pg_amcheck
suggest that command_checks_all() perform shell expansion on some
machines but not others, apparently due to an underlying behavior
difference in IPC::Run. Let's see if we can work around that - and
confirm that it is the real problem - by passing '-S*' as a single
argument rather than '-S' and '*' as two separate ones.

Failures were observed on jacana and hoverfly.

Mark Dilger

Discussion: http://postgr.es/m/9E76E46A-48B2-4869-BD0C-422204C1F767@enterprisedb.com