[co19] Roll co19 to d50a305d1b4455b4e72ba45a2cf2ab1c37004bc6

2024-11-28 sgrekhov22@gmail.com dart-lang/co19#2976. Update assertion texts according to the new spec (dart-lang/co19#3000)
2024-11-28 sgrekhov22@gmail.com dart-lang/co19#2119. Add issue number to other_declarations_A04_t07.dart (dart-lang/co19#3001)
2024-11-28 sgrekhov22@gmail.com dart-lang/co19#2976. Add semantics tests (dart-lang/co19#2998)
2024-11-27 sgrekhov22@gmail.com Fixes dart-lang/co19#2996. Update CFE expected errors locations (dart-lang/co19#2999)
2024-11-25 sgrekhov22@gmail.com dart-lang/co19#2559. Add extension types and enums to augmenting constructors test. Part 2. (dart-lang/co19#2972)
2024-11-25 sgrekhov22@gmail.com dart-lang/co19#2956. Add more type `void` tests (dart-lang/co19#2997)

Cq-Include-Trybots: luci.dart.try:analyzer-linux-release-try
Change-Id: I858dbf6908fe32f38a401ce4ebfe120e064de4aa
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/398160
Reviewed-by: Alexander Thomas <athom@google.com>
Commit-Queue: Alexander Thomas <athom@google.com>
Reviewed-by: Erik Ernst <eernst@google.com>

DEPS

@@ -54,7 +54,7 @@ vars = {
 
   # co19 is a cipd package automatically generated for each co19 commit.
   # Use tests/co19/update.sh to update this hash.
-  "co19_rev": "991e2f1664c64d455e0b22f0d5de45e384d5a90f",
+  "co19_rev": "d50a305d1b4455b4e72ba45a2cf2ab1c37004bc6",
 
   # The internal benchmarks to use. See go/dart-benchmarks-internal
   "benchmarks_internal_rev": "3bd6bc6d207dfb7cf687537e819863cf9a8f2470",