Content assist proposal that adds import fails if config script or AST transform adds imports

[eric-milles]

With this set as the compiler config script, code completion in the default package fails with exception in import region determination. There is no package statement to denote the start of the imports region.

withConfig(configuration) {
  imports {
    star 'java.util.regex'
  }
}

Completion of the TypeChecked proposal at the caret fails to apply the import edit.

@TypeCh|
class C {
}