Make our outputs precious
Make our outputs precious

This change marks our compiled tests as "Precious" which means they
won't be deleted when a test fails. This makes it much easier to
re-run the test by hand inside gdb/lldb.

wcs1only/s2n,gibson-compsci/s2n,PKRoma/s2n,alexeblee/s2n,alexeblee/s2n,alexeblee/s2n,bpdavidson/s2n,raycoll/s2n,wcs1only/s2n,PKRoma/s2n,bpdavidson/s2n,awslabs/s2n,raycoll/s2n,jldodds/s2n,raycoll/s2n,colmmacc/s2n,alexeblee/s2n,raycoll/s2n,awslabs/s2n,wcs1only/s2n,alexeblee/s2n,awslabs/s2n,jldodds/s2n,awslabs/s2n,wcs1only/s2n,wcs1only/s2n,colmmacc/s2n,jldodds/s2n,wcs1only/s2n,alexeblee/s2n,gibson-compsci/s2n,bpdavidson/s2n,bpdavidson/s2n,awslabs/s2n,raycoll/s2n,colmmacc/s2n,jldodds/s2n,raycoll/s2n,PKRoma/s2n,jldodds/s2n,colmmacc/s2n,gibson-compsci/s2n,bpdavidson/s2n,PKRoma/s2n,colmmacc/s2n,PKRoma/s2n,PKRoma/s2n,wcs1only/s2n,colmmacc/s2n,gibson-compsci/s2n,awslabs/s2n,PKRoma/s2n,gibson-compsci/s2n,PKRoma/s2n,bpdavidson/s2n,wcs1only/s2n,gibson-compsci/s2n