Changelog:

• Language Features:
  • General: Add equality-comparison operators for external function types.
  • General: Support ContractName.functionName for abi.encodeCall, in addition to external function pointers.
• Compiler Features:
  • Commandline Interface: Event and error signatures are also returned when using --hashes.
  • Yul Optimizer: Remove mstore and sstore operations if the slot already contains the same value.
  • Yul: Emit immutable references for pure yul code when requested.
• Bugfixes:
  • Antlr Grammar: Allow builtin names in yulPath to support .address in function pointers.
  • Code Generator: Fix internal error when accessing the members of external functions occupying more than two stack slots.
  • Code Generator: Fix internal error when doing an explicit conversion from string calldata to bytes.
  • Control Flow Graph: Perform proper virtual lookup for modifiers for uninitialized variable and unreachable code analysis.
  • General: string.concat now properly takes strings as arguments and returns string memory. It was accidentally introduced as a copy of bytes.concat before.
  • Immutables: Fix wrong error when the constructor of a base contract uses return and the derived contract contains immutable variables.
  • Inheritance: Consider functions in all ancestors during override analysis.
  • IR Generator: Add missing cleanup during the conversion of fixed bytes types to smaller fixed bytes types.
  • IR Generator: Add missing cleanup for indexed event arguments of value type.
  • IR Generator: Fix internal error when copying reference types in calldata and storage to struct or array members in memory.
  • IR Generator: Fix IR syntax error when copying storage arrays of structs containing functions.
  • Natspec: Fix internal error when overriding a struct getter with a Natspec-documented return value and the name in the struct is different.
  • Type Checker: Fix internal error when a constant variable declaration forward references a struct.
  • Yul EVM Code Transform: Improved stack shuffling in corner cases.
• Solc-Js:
  • The wrapper now requires at least nodejs v10.
  • The code has been ported to TypeScript.
• Build System:
  • Emscripten builds store the embedded WebAssembly binary in LZ4 compressed format and transparently decompress on loading.

Successfully compiled and deployed the sample programs from the official Solidity examples (https://docs.soliditylang.org/en/latest/solidity-by-example.html).

Signed-off-by: Gavin Zhao <gavinzhaojw@protonmail.com>