Compiler crashes when using ref_extern member variable in class

[ijsf]

Bug description

The compiler crashes whenever a ref_extern is used as a member variable of a class. Also happens for similar reference types (e.g. ref_func) or nullable reference types (e.g. externref).

Steps to reproduce

Use the following code:

class MyWrapper {
  ref: externref;
}
let mywrapper = new MyWrapper();

This causes a compiler assertion:

Whoops, the AssemblyScript compiler has crashed during compile :-(
▌
▌ Here is the stack trace hinting at the problem, perhaps it's useful?
▌
▌ AssertionError: assertion failed
▌     at Y.assert (.\wasm\node_modules\assemblyscript\std\portable\index.js:216:11)
▌     at Kn.finishResolveClass (.\wasm\node_modules\assemblyscript\src\resolver.ts:3433:19)
▌     at Kn.resolveClass (.\wasm\node_modules\assemblyscript\src\resolver.ts:3222:10)
▌     at Kn.resolveClassInclTypeArguments (.\wasm\node_modules\assemblyscript\src\resolver.ts:3652:17)
▌     at jr.compileNewExpression (.\wasm\node_modules\assemblyscript\src\compiler.ts:8710:37)
▌     at jr.compileExpression (.\wasm\node_modules\assemblyscript\src\compiler.ts:3397:21)
▌     at jr.compileGlobal (.\wasm\node_modules\assemblyscript\src\compiler.ts:1183:25)
▌     at jr.compileTopLevelStatement (.\wasm\node_modules\assemblyscript\src\compiler.ts:2125:20)
▌     at jr.compileFile (.\wasm\node_modules\assemblyscript\src\compiler.ts:1099:12)
▌     at jr.compile (.\wasm\node_modules\assemblyscript\src\compiler.ts:548:14)
▌
▌ If you see where the error is, feel free to send us a pull request. If not,
▌ please let us know: https://github.com/AssemblyScript/assemblyscript/issues
▌
▌ Thank you!

AssemblyScript version

0.27.6

[dcodeIO]

Fixed by emitting a proper "Not implemented" error in #2733, thanks @CountBleck!