Replace mmap with file io in merkle tree hash calculation #16677

Job	Run time
cargo-test-sbf (associated-token-account)	8m 28s
check (associated-token-account)	2m 54s
cargo-test-sbf (feature-proposal)	7m 21s
check (feature-proposal)	3m 3s
cargo-test-sbf (instruction-padding)	5m 37s
check (instruction-padding)	2m 29s
cargo-test-sbf (memo)	6m 55s
test_cli (single-pool)	16m 48s
check (memo)	1m 8s
cargo-test-sbf (record)	6m 11s
test_cli (token-2022)	14m 32s
check (record)	1m 47s
cargo-test-sbf (single-pool)	10m 58s
check (single-pool)	1m 51s
cargo-test-sbf (slashing)	13m 5s
check (slashing)	1m 51s
cargo-test-sbf (stake-pool)	12m 15s
check (stake-pool)	1m 34s
cargo-test-sbf (token-2022)	6m 23s
check (token-2022)	5m 47s
	2h 10m 57s

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