Unfuturize performance future for Locale array access

I stumbled across this while looking thru the test logs.

This test should have changed when the comm diags were moved out of
ChapelLocale (r20874), but alas Brad had not yet added the .bad
capability.  Added 'use CommDiagnostics' which fixes the compilation
error we were getting.

Now that it compiles, it satisfies this performance future request due
to the replicate RootLocale change (r21725), so I'm removing the
future.



git-svn-id: http://svn.code.sf.net/p/chapel/code/trunk@21840 3a8e244f-b0f2-452b-bcba-4c88e055c3ca