Incorrect return type on an @FfiNative annotation causes segfault at runtime

[dnfield]

Ideally there would be analysis and even compilation issues with this:

BAD:

  @FfiNative<Handle Function(Pointer<Void>, Uint32, Uint32, Handle)>('Picture::toImageSync')
  external void _toImageSync(int width, int height, _Image outImage);

GOOD:

  @FfiNative<Void Function(Pointer<Void>, Uint32, Uint32, Handle)>('Picture::toImageSync')
  external void _toImageSync(int width, int height, _Image outImage);

Ideally the compiler or analyzer would have told me there's a mismatch between the return signature of the function and the generic parameter of the annotation. This was due to a copy paste error on my end, and resulted in a segfault at runtime that produced lots unsymbolized frames even in an unopt build.

@dcharkes maybe?

[dcharkes]

I recently discovered the same issue in the analzyer:

• [analyzer/ffi] FfiNatives don't check whether the native types are native and correspond to the Dart types #49412

I was under the impression this was only missing in the analyzer and that the CFE did check this report compilation errors. I will double check this.