[co19] Roll co19 to a2637f56e917c46d7055d7c857915b461837dfe6

2024-05-03 sgrekhov22@gmail.com Fixes dart-lang/co19#2635. Use null-aware operator to invoke function via nullable variable (dart-lang/co19#2636)
2024-05-02 sgrekhov22@gmail.com dart-lang/co19#2559. Add more augmented expression tests for local variables in field initializers (dart-lang/co19#2634)
2024-05-02 sgrekhov22@gmail.com dart-lang/co19#2559. Add more augmented expression tests for local variables inside of getters and setters (dart-lang/co19#2633)
2024-05-02 sgrekhov22@gmail.com dart-lang/co19#2559. Add augmented expression tests for functions (dart-lang/co19#2630)
2024-05-01 49699333+dependabot[bot]@users.noreply.github.com Bump actions/checkout from 4.1.2 to 4.1.4 (dart-lang/co19#2632)
2024-05-01 sgrekhov22@gmail.com dart-lang/co19#2559. Make more augmented expression tests stronger (dart-lang/co19#2629)
2024-05-01 sgrekhov22@gmail.com Fixes dart-lang/co19#2574. Expect an error in case of augmenting a type alias (dart-lang/co19#2627)
2024-04-30 sgrekhov22@gmail.com dart-lang/co19#2559. Add augmenting expression tests for fields with no initializers (dart-lang/co19#2626)
2024-04-30 sgrekhov22@gmail.com dart-lang/co19#2559. Make augmented expression tests stronger (dart-lang/co19#2628)
2024-04-29 sgrekhov22@gmail.com Fixes dart-lang/co19#2624. Add more extension type tests for union types (dart-lang/co19#2625)
2024-04-26 sgrekhov22@gmail.com dart-lang/co19#2559. Add augmenting expression tests for fields (dart-lang/co19#2621)

Change-Id: I8246f841afd24390742ba225e769ba881dccef9b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/365261
Reviewed-by: Alexander Thomas <athom@google.com>
Commit-Queue: Erik Ernst <eernst@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": "c18ac1b2cb497b23fcb3c8d04cdab1069cd16e2b",
+  "co19_rev": "a2637f56e917c46d7055d7c857915b461837dfe6",
 
   # The internal benchmarks to use. See go/dart-benchmarks-internal
   "benchmarks_internal_rev": "a7c23b2422492dcc515d1ba4abe3609b50e2a139",