Allow ref (&) parameters in contract fns #111

Job	Run time
collect-examples	18s
test-example (custom_types)	1m 15s
test-example (events)	1m 18s
test-example (increment_with_fuzz)	1m 43s
test-example (cross_contract/contract_b)	1m 33s
test-example (bls_signature)	1m 27s
test-example (cross_contract/contract_a)	1m 17s
test-example (deployer/deployer)	1m 40s
test-example (deployer/contract)	1m 9s
test-example (increment_with_pause)	1m 29s
test-example (simple_account)	1m 14s
test-example (pause)	1m 14s
test-example (import_ark_bn254)	1m 33s
test-example (increment)	1m 18s
test-example (multisig_1_of_n_account/contract)	1m 19s
test-example (auth)	1m 19s
test-example (atomic_multiswap)	1m 37s
test-example (token)	1m 17s
test-example (alloc)	1m 21s
test-example (liquidity_pool)	1m 18s
test-example (fuzzing)	1m 51s
test-example (other_custom_types)	1m 11s
test-example (atomic_swap)	1m 29s
test-example (timelock)	1m 11s
test-example (mint-lock)	1m 21s
test-example (hello_world)	1m 17s
test-example (single_offer)	1m 16s
test-example (merkle_distribution)	1m 30s
test-example (upgradeable_contract/old_contract)	1m 23s
test-example (logging)	1m 17s
test-example (errors)	1m 14s
test-example (account)	1m 18s
test-example (deep_contract_auth)	1m 19s
test-example (upgradeable_contract/new_contract)	1m 12s
test-example (eth_abi)	1m 32s
test-example (groth16_verifier)	1m 19s
test-example (ttl)	1m 20s
	49m 39s

Provide feedback