Kani

Add harnesses for safety of primitive conversions #1242

Job	Run time
Verify std library (partition 1)	36m 8s
Kani List	11m 51s
Verify std library (partition 2)	42m 38s
Verify std library (partition 3)	35m 2s
Verify std library (partition 4)	44m 23s
Verify std library (partition 1)	25m 10s
Verify std library (partition 2)	37m 31s
Verify std library (partition 3)	35m 31s
Verify std library (partition 4)	41m 38s
	5h 9m 52s

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