Adjust JIT automated testing for tiered compilation (#18828)
Adjust JIT automated testing for tiered compilation (#18828)

Make it explicit that most JIT testing does not use tiered compilation regardless of the runtime default
Clone jitstress1/2 and r2r_jitstress1/2 test modes both with and without tiering.
Move the existing tieredcompilation test modes to have the same periodic scheduling as other jit test runs.

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