co19/LanguageFeatures/Patterns/scope_A04_t03: type 'Scope' is not a subtype of type 'Token' of ' in type cast'

[alexmarkov]

Part of #49749.

co19/LanguageFeatures/Patterns/scope_A04_t03 crashes front-end in the following way:

Crash when compiling file:///b/s/w/ir/tests/co19/src/LanguageFeatures/Patterns/scope_A04_t03.dart at character offset 1455:
type 'Scope' is not a subtype of type 'Token' of ' in type cast'

#0      BodyBuilder.endIfControlFlow (package:front_end/src/fasta/kernel/body_builder.dart:6482:27)
#1      IfComplete.parse (package:_fe_analyzer_shared/src/parser/literal_entry_info_impl.dart:212:23)
#2      Parser.parseLiteralListSuffix (package:_fe_analyzer_shared/src/parser/parser_impl.dart:6502:24)
#3      Parser.parsePrimary (package:_fe_analyzer_shared/src/parser/parser_impl.dart:6231:14)
#4      Parser.parseUnaryExpression (package:_fe_analyzer_shared/src/parser/parser_impl.dart:6081:12)
#5      Parser.parsePrecedenceExpression (package:_fe_analyzer_shared/src/parser/parser_impl.dart:5627:13)
#6      Parser.parseExpression (package:_fe_analyzer_shared/src/parser/parser_impl.dart:5567:15)
#7      Parser.parseReturnStatement (package:_fe_analyzer_shared/src/parser/parser_impl.dart:5470:13)
#8      Parser.parseStatementX (package:_fe_analyzer_shared/src/parser/parser_impl.dart:5342:14)
#9      Parser.parseStatement (package:_fe_analyzer_shared/src/parser/parser_impl.dart:5315:20)
#10     Parser.parseFunctionBody (package:_fe_analyzer_shared/src/parser/parser_impl.dart:5220:15)
#11     DietListener.buildFunctionBody (package:front_end/src/fasta/source/diet_listener.dart:1120:14)
#12     DietListener.endTopLevelMethod (package:front_end/src/fasta/source/diet_listener.dart:376:5)
#13     Parser.parseTopLevelMethod (package:_fe_analyzer_shared/src/parser/parser_impl.dart:3682:14)
#14     Parser.parseTopLevelMemberImpl (package:_fe_analyzer_shared/src/parser/parser_impl.dart:3424:14)
#15     Parser.parseTopLevelDeclarationImpl (package:_fe_analyzer_shared/src/parser/parser_impl.dart:606:14)
#16     Parser.parseUnit (package:_fe_analyzer_shared/src/parser/parser_impl.dart:403:15)
#17     SourceLoader.buildBody (package:front_end/src/fasta/source/source_loader.dart:1267:12)
<asynchronous suspension>
#18     SourceLoader.buildBodies (package:front_end/src/fasta/source/source_loader.dart:676:7)
<asynchronous suspension>
#19     KernelTarget.buildComponent.<anonymous closure> (package:front_end/src/fasta/kernel/kernel_target.dart:611:7)
<asynchronous suspension>
#20     withCrashReporting (package:front_end/src/fasta/crash.dart:136:12)
<asynchronous suspension>
#21     _buildInternal (package:front_end/src/kernel_generator_impl.dart:206:19)
<asynchronous suspension>
#22     withCrashReporting (package:front_end/src/fasta/crash.dart:136:12)
<asynchronous suspension>
#23     generateKernel.<anonymous closure> (package:front_end/src/kernel_generator_impl.dart:48:12)
<asynchronous suspension>
#24     generateKernel (package:front_end/src/kernel_generator_impl.dart:47:10)
<asynchronous suspension>
#25     kernelForModule (package:front_end/src/api_prototype/kernel_generator.dart:100:11)
<asynchronous suspension>
#26     SingleShotCompilerWrapper.compileInternal (file:///b/s/w/ir/cache/builder/sdk/pkg/vm/bin/kernel_service.dart:407:11)
<asynchronous suspension>
#27     Compiler.compile.<anonymous closure> (file:///b/s/w/ir/cache/builder/sdk/pkg/vm/bin/kernel_service.dart:215:45)
<asynchronous suspension>
#28     _processLoadRequest (file:///b/s/w/ir/cache/builder/sdk/pkg/vm/bin/kernel_service.dart:889:37)
<asynchronous suspension>

--- Re-run this test:
python3 tools/test.py -n dartk-strong-linux-release-x64 co19/LanguageFeatures/Patterns/scope_A04_t03

@johnniwinther @chloestefantsova

[chloestefantsova]

This appears to be fixed.