Fasta generates Kernel that does not correspond to the original code AST

[scheglov]

For the following code:

class C {}
const V = const C.named();

The following Kernel is generated.

library;
import self as self;
import "dart:core" as core;

class C extends core::Object {
  default constructor •() → void
    : super core::Object::•()
    ;
}
static const field dynamic V = const core::_ConstantExpressionError::•()._throw(new core::_CompileTimeError::•("file:///test.dart:2:17: Error: Method not found: 'C.named'.\nconst V = const C.named();\n                ^"));

As you can see, it does not correspond to the original Dart code - there is no _throw in the Dart code, and both C and named are lost. There is no way for Analyzer to resynthesize correct element model from this Kernel.

[sigmundch]

Let's make sure to discuss this in detail as soon as we are all available (I believe Peter is out this week).

This falls under the general umbrella of how do we want to represent erroneous code and handle error recovery.

@scheglov you might be interested also in #29840, where Peter was proposing changes to the IR to represent these erroneous cases like these.