Parser fuzz crash: GenericFunctionTypeImpl is not a subtype of type TypeName

[MichaelRFairhurst]

class T=Function<>(

Unhandled exception:
type 'GenericFunctionTypeImpl' is not a subtype of type 'TypeName'
#0      AstBuilder.endNamedMixinApplication (package:analyzer/src/fasta/ast_builder.dart:1800:14)
#1      Parser.parseNamedMixinApplication (package:front_end/src/fasta/parser/parser.dart:1780:14)
#2      Parser.parseClassOrNamedMixinApplication (package:front_end/src/fasta/parser/parser.dart:1761:14)
#3      Parser.parseTopLevelKeywordDeclaration (package:front_end/src/fasta/parser/parser.dart:572:14)
#4      Parser.parseTopLevelDeclarationImpl (package:front_end/src/fasta/parser/parser.dart:468:14)
#5      Parser.parseUnit (package:front_end/src/fasta/parser/parser.dart:350:15)
#6      ParserAdapter.parseCompilationUnit2 (package:analyzer/src/generated/parser_fasta.dart:159:32)
#7      ParserAdapter.parseCompilationUnit (package:analyzer/src/generated/parser_fasta.dart:154:12)
#8      _File._parse (package:analyzer/src/services/available_declarations.dart:1863:23)
#9      _File.refresh (package:analyzer/src/services/available_declarations.dart:1184:30)
#10     DeclarationsTracker._getFileByPath (package:analyzer/src/services/available_declarations.dart:691:14)