Update EIP-7937: Replace “MUST OOG” with “MUST halt with an invalid instruction exception”

[phrwlk]

• Problem: The spec incorrectly stated “MUST OOG” for two invalid-instruction cases: (1) when the second byte after the C0 prefix is not a valid 64-bit opcode, and (2) when executing C0 JUMPDEST. In EVM semantics, these are invalid instruction halts, not out-of-gas.
• What was wrong: Misuse of OOG terminology for invalid opcode scenarios, conflicting with the Yellow Paper and established - EIPs.
• Fix: Updated wording to “MUST halt with an invalid instruction exception” at both locations (invalid C0 xx; C0 JUMPDEST) to align with EVM behavior.

[eth-bot]

File EIPS/eip-7937.md

Requires 1 more reviewers from @sorpaas