Regen tests

test/codegen/expect/collection/src/unmodifiable_wrappers.txt

Index: test/codegen/expect/collection/src/unmodifiable_wrappers.txt
diff --git a/test/codegen/expect/collection/src/unmodifiable_wrappers.txt b/test/codegen/expect/collection/src/unmodifiable_wrappers.txt
index df68cc8a6f38f1ba2d944defb6ab99b65dd7f540..34d80d54e99c4ba8eb7ddc9117e32c4c24a601b5 100644
--- a/test/codegen/expect/collection/src/unmodifiable_wrappers.txt
+++ b/test/codegen/expect/collection/src/unmodifiable_wrappers.txt
@@ -1,5 +1,7 @@
 // Messages from compiling unmodifiable_wrappers.dart
-warning: [DOWN_CAST_COMPOSITE] _throw() (dynamic) will need runtime check to cast to type E (package:collection/src/unmodifiable_wrappers.dart, line 88, col 28)
-warning: [DOWN_CAST_COMPOSITE] _throw() (dynamic) will need runtime check to cast to type E (package:collection/src/unmodifiable_wrappers.dart, line 94, col 21)
-warning: [DOWN_CAST_COMPOSITE] _throw() (dynamic) will need runtime check to cast to type V (package:collection/src/unmodifiable_wrappers.dart, line 218, col 41)
-warning: [DOWN_CAST_COMPOSITE] _throw() (dynamic) will need runtime check to cast to type V (package:collection/src/unmodifiable_wrappers.dart, line 230, col 27)
+severe: [AnalyzerMessage] Missing concrete implementation of 'Iterable.map' and 'Iterable.expand' (package:collection/src/unmodifiable_wrappers.dart, line 20, col 7)
+severe: [AnalyzerMessage] Missing concrete implementation of 'Iterable.expand' and 'Iterable.map' (package:collection/src/unmodifiable_wrappers.dart, line 93, col 7)
+warning: [DOWN_CAST_COMPOSITE] _throw() (dynamic) will need runtime check to cast to type E (package:collection/src/unmodifiable_wrappers.dart, line 59, col 28)
+warning: [DOWN_CAST_COMPOSITE] _throw() (dynamic) will need runtime check to cast to type E (package:collection/src/unmodifiable_wrappers.dart, line 63, col 21)
+warning: [DOWN_CAST_COMPOSITE] _throw() (dynamic) will need runtime check to cast to type V (package:collection/src/unmodifiable_wrappers.dart, line 151, col 41)
+warning: [DOWN_CAST_COMPOSITE] _throw() (dynamic) will need runtime check to cast to type V (package:collection/src/unmodifiable_wrappers.dart, line 159, col 27)