[CFE] Transform spread and if in const collections early.

This makes sure that the AST before constant evaluation only contains
official kernel nodes.

Fixes https://github.com/dart-lang/sdk/issues/36910

Change-Id: Ic4e8e15adeaea8ad4700d6feb67e31f5f0a54f7f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/103123
Reviewed-by: Kevin Millikin <kmillikin@google.com>

https://dart.googlesource.com/sdk/+/f051cd5b4d156e7ae54c44ba19c343607c62d5df
1 file changed
tree: 769bcd4e08a7e1846ad5df6bdb1de763e35db193
  1. commits.json