Named parameters of generic functions should have names.

pkg/analyzer/lib/src/generated/parser.dart

Index: pkg/analyzer/lib/src/generated/parser.dart
diff --git a/pkg/analyzer/lib/src/generated/parser.dart b/pkg/analyzer/lib/src/generated/parser.dart
index 3c2f00c3e823945c3f11ddd3c9fed0d3d2618bf6..92b5d0ea179525758bf4e485afcdb9bb9cc7b4d8 100644
--- a/pkg/analyzer/lib/src/generated/parser.dart
+++ b/pkg/analyzer/lib/src/generated/parser.dart
@@ -2907,6 +2907,7 @@ class Parser {
           parameter.identifier == null) {
         _reportErrorForCurrentToken(
             ParserErrorCode.MISSING_NAME_FOR_NAMED_PARAMETER);
+        parameter.identifier = createSyntheticIdentifier(isDeclaration: true);
       }
       return astFactory.defaultFormalParameter(
           parameter, kind, separator, defaultValue);
@@ -2930,6 +2931,7 @@ class Parser {
           parameter.identifier == null) {
         _reportErrorForCurrentToken(
             ParserErrorCode.MISSING_NAME_FOR_NAMED_PARAMETER);
+        parameter.identifier = createSyntheticIdentifier(isDeclaration: true);
       }
       return astFactory.defaultFormalParameter(
           parameter, kind, separator, defaultValue);
@@ -2939,6 +2941,7 @@ class Parser {
           parameter.identifier == null) {
         _reportErrorForCurrentToken(
             ParserErrorCode.MISSING_NAME_FOR_NAMED_PARAMETER);
+        parameter.identifier = createSyntheticIdentifier(isDeclaration: true);
       }
       return astFactory.defaultFormalParameter(parameter, kind, null, null);
     }