Reduce the number of innerloop CoreFX jobs
Reduce the number of innerloop CoreFX jobs

1. Stop doing any OSX CoreFX jobs; they're too unreliable.
2. Stop running Debug jobs.

wtgodbe/coreclr,mmitche/coreclr,mmitche/coreclr,krk/coreclr,poizan42/coreclr,wtgodbe/coreclr,mmitche/coreclr,poizan42/coreclr,krk/coreclr,krk/coreclr,wtgodbe/coreclr,mmitche/coreclr,poizan42/coreclr,krk/coreclr,cshung/coreclr,poizan42/coreclr,wtgodbe/coreclr,wtgodbe/coreclr,poizan42/coreclr,poizan42/coreclr,mmitche/coreclr,cshung/coreclr,cshung/coreclr,wtgodbe/coreclr,cshung/coreclr,krk/coreclr,mmitche/coreclr,cshung/coreclr,cshung/coreclr,krk/coreclr