SIMD-0645: SVM JIT intrinsics sol_multi3

SIMD-0645 (SVM JIT intrinsics sol_multi3) is a Solana Improvement Document; proposed in an open pull request.

No feature gate implements it.

Vortex

• Consensus leaderboard
• Fees leaderboard
• Validators
• Stake pools
• Decentralization
• Client versions
• Cluster status
• Governance
• Feature gates
• SIMDs
• Activity
• API and AI usage