feat(solc): set default EVM version to Shanghai (gakonst#2414)

* feat(solc): set default EVM version to Shanghai

* feat: add PUSH0 opcode

* feat: alias DIFFICULTY to PREVRANDAO

* ci: install solc 0.8.20

* add new modelchecker options, AST, and fix tests

* fix: `ContractDefinition.internalFunctionIDs`

* chore: remove uses of dbg!

* update test

* update

Author: DaniPopes

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ env:
     ETHERSCAN_API_KEY: "I5BXNZYP5GEDWFINGVEZKYIVU2695NPQZB"
     GOERLI_PRIVATE_KEY: "fa4a1a79e869a96fcb42727f75e3232d6865a82ea675bb95de967a7fe6a773b2"
     GETH_BUILD: "1.11.2-73b01f40"
-    SOLC_VERSION: "0.8.19"
+    SOLC_VERSION: "0.8.20"
     CARGO_TERM_COLOR: always
 
 jobs: