AVM: sha512 opcode, txn commitments,

[jannotti]

Summary

This PR provides access to previous block's txn commitments in the AVM, the sha512 hash of the previous block, and a sha512 opcode so that programs could use these things.

The sha512 cost adjusts for length. The existing hashes (sha512_256, keecak, sha256) should probably all be adjusted to do so as well. (sha512_256 would presumably get the same cost as sha512).

Test Plan

[Copilot]

Pull Request Overview

This PR introduces SHA-512 cryptographic capabilities to the Algorand Virtual Machine (AVM) by adding a new sha512 opcode and providing access to transaction commitments from previous blocks using different hash algorithms.

• Adds the sha512 opcode with cost adjustments based on input length
• Introduces new block fields for accessing previous block's transaction commitments (sha512_256, sha256, sha512) and wider sha-512 hash
• Updates syntax highlighting and documentation to include the new cryptographic functionality

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
data/transactions/logic/opcodes.go	Adds the sha512 opcode definition with version 13 and length-based cost calculation
data/transactions/logic/crypto.go	Implements the opSHA512 function that computes SHA-512 hash
data/transactions/logic/fields.go	Defines new block fields for transaction commitments and sha512 hash access
data/transactions/logic/eval.go	Implements block field evaluation for the new commitment and hash fields
data/transactions/logic/fields_string.go	Updates string representations for new block fields
data/transactions/logic/doc.go	Adds documentation and categorization for the sha512 opcode
data/transactions/logic/teal.tmLanguage.json	Updates TEAL syntax highlighting to include sha512
data/transactions/logic/assembler_test.go	Adds test cases for sha512 opcode and new block fields
data/transactions/logic/crypto_test.go	Includes sha512 in cryptographic benchmark tests

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[algorandskiy]

looks like there should be a test checking the opcode against some blob with known sha512 hash?

[jannotti]

looks like there should be a test checking the opcode against some blob with known sha512 hash?

Added in 14b53f0