The "additionalExports" are sorted in production code to give stable
output.
Before this CL it did `toString()` on the canonical names which is
O(n^2) because of continued string concatenation.
This CL changes it to sort on the name, going to the parent if it's the
same. This _does_ change the sorting, but should still be stable.
When compiling via the flutter frontend try bot the time spent on
sorting does from ~45 seconds to ~9 seconds (arguable still a lot, but
much better).
This will also speed up flutter testing because it will spend less time
waiting for the frontend.
TEST=Assuming existing tests.
Change-Id: If350b7c2ce49f00b2924732a7fa7eb51c38c8172
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/322280
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Jens Johansen <jensj@google.com>
Jens Johansen
9f9da91b84