fix failing stRandom ETC tests for core-geth,go-ethereum

[meowsbits]

Tests

• Target test: GeneralStateTests/stRandom/randomStatetest246.json
  This test is not the only one failing, but its my target test case, which I expect to be representative of a systemic issue.

Clients

• etclabscorecore-geth@merge/foundation-release/1.10.23-tests-generate-fixes-statefix-difficulty-test-v2-ripemd-tx-debug-no-ripemd-hack-evmc-dimitrys-etc-tests
• etclabscore/ethereum/go-ethereum@etc-treads-lightly-retests
• etccooperative/erigon@devel+classic

Summary/Notes

I see a mismatch on the stack with DIFFICULTY opcode; core-geth and go-ethereum both push 0; erigon pushes 0x20000.
I expect the value should be non-zero, since EIP-1559 is not activated for the ETC_* forks.

disasm <<< "434241314441434293170955"                                                                                 
434241314441434293170955
0      NUMBER
1      TIMESTAMP
2      COINBASE
3      BALANCE
4      DIFFICULTY
5      COINBASE
6      NUMBER
7      TIMESTAMP
8      SWAP4
9      OR
10     MULMOD
11     SSTORE

cat .ia/run-failing-state-test.sh
#!/usr/bin/env bash

testspath=~/go/src/github.com/ethereum/go-ethereum/tests/testdata-etc/GeneralStateTests/stRandom/randomStatetest246.json

~/go/src/github.com/ethereum/go-ethereum/build/bin/evm --dump --debug statetest "${testspath}" |& tee /tmp/core-geth_strand246.out
~/dev/ledgerwatch/erigon/build/bin/evm --dump --debug statetest "${testspath}" |& tee /tmp/erigon_strand246.out
~/dev/ethereum/go-ethereum/build/bin/evm --dump --debug statetest "${testspath}" |& tee /tmp/geth_strand246.out