ECIP-1061: Move Aztlan to Phoenix block on Mordor; ECIP-1086 Last Call

[soc1c]

The rationale is taken from #295

• revert mordor and have a proper phoenix + aztlan hardfork
• keep kotti with ecip-1086 ECIP-1086: SLOAD Gas Patch for the Testnets #293

cc @meowsbits

[meowsbits]

Should be broken into 1 pull request for each ECIP modified (2 pull requests).

EDIT: i can't seem to be able to drop this request-changes review (or to modify it to a comment)... ?

See "It modifies an Accepted ECIP" for my real remaining reason for request-changes review: #296 (review)

[soc1c]

@meowsbits no. because the changes proposed are not standalone. this should be accepted as bundle or rejected as bundle. but you wouldn't be able to pick from the two change sets.

[meowsbits]

It modifies an Accepted ECIP... ?

[meowsbits]

With my latest understanding of EIP2200 SLOAD gas specification (and related patches), it seems to me that ECIP1086 is invalid/useless, since because EIP2200 does not specify SLOAD gas=800, no patch should be implemented (or now, should actually be reverted in some client cases), and ECIP1086 as a "retrospective allowance" for the EIP2200 gas=200 become a no-op.

[meowsbits]

Would the Mordor revert reuse the same genesis, or a new one to prevent forks?

[soc1c]

Closing in favor of #297