[CFE] Constant evaluator benchmark

E.g. one can run a benchmark via something like
`out/ReleaseX64/dart pkg/front_end/test/constant_evaluator_benchmark.dart --platform=out/ReleaseX64/vm_platform_strong.dill pkg/compiler/bin/dart2js.dart --target=VM`

Change-Id: Ie9202bbd8a390a461a31625880bbb182f845261e
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/168485
Commit-Queue: Jens Johansen <jensj@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>

https://dart.googlesource.com/sdk/+/08f3b03361cc89d809eccdfb70c48f864365dd0d
diff --git a/commits.json b/commits.json
index 8c856b1..cab5592 100644
--- a/commits.json
+++ b/commits.json
@@ -1,5 +1,5 @@
 {
   "external/github.com/flutter/engine":"a4ce848dfb6fb002544494e762f53a826830cc1d",
   "external/github.com/flutter/flutter":"a7f5fd5360007518644597c60a1f2169eacccc2b",
-  "sdk":"9b5764d05ddf09d08950084290cf7e7c6464cecb"
+  "sdk":"08f3b03361cc89d809eccdfb70c48f864365dd0d"
 }
\ No newline at end of file