This adds FileUriConstantExpression, a subclass of ConstantExpression, to support correct file offset of annotations for augmentations and patches.
The FileUriExpression is used to carry the file uri of the expression
before constant evaluation.
TEST=general/patch_annotations
Change-Id: I0dc8a0cb97dd530fd1960785d38c2d5e4883c3dd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/311660
Commit-Queue: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Jens Johansen <jensj@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>