[co19] Roll co19_2 to e48b3090826cf40b8037648f19d211e8eab1b4b6

2020-07-16 [email protected] Fixes 837. It is allowed to import/export libraries with the same name now
2020-07-13 [email protected] Fixes 806. Mixin cannot be derived from its superclass

Change-Id: I0dfd9ed29da07f9855c36a784565bb3940ba4fe2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/155761
Reviewed-by: Jonas Termansen <[email protected]>

Author: whesse

DEPS

@@ -45,7 +45,7 @@ vars = {
   # hashes. It requires access to the dart-build-access group, which EngProd
   # has.
   "co19_rev": "d79951e06e443213243e54c2c32694b79a221b65",
-  "co19_2_rev": "620c1148c8b7a3d7f74afacf348c46f109eb64f2",
+  "co19_2_rev": "e48b3090826cf40b8037648f19d211e8eab1b4b6",
 
   # The internal benchmarks to use. See go/dart-benchmarks-internal
   "benchmarks_internal_rev": "0e59a6bc3ee912273865b87709cdb698be358e30",