[CFE, Patterns] "Null check operator used on a null value" at new Name.byReference

[alexmarkov]

CFE crashes on co19/LanguageFeatures/Patterns/wildcards_A03_t01 test:

Crash when compiling file:///b/s/w/ir/tests/co19/src/LanguageFeatures/Patterns/wildcards_A03_t01.dart at character offset 1066:
Null check operator used on a null value

#0      new Name.byReference (package:kernel/ast.dart:11503:48)
#1      new Name (package:kernel/ast.dart:11496:11)
#2      InferenceVisitorImpl.resolveObjectPatternPropertyGet (package:front_end/src/fasta/type_inference/inference_visitor.dart:10871:27)
#3      TypeAnalyzer.analyzeObjectPattern (package:_fe_analyzer_shared/src/type_inference/type_analyzer.dart:1149:11)
#4      InferenceVisitorImpl.visitObjectPattern (package:front_end/src/fasta/type_inference/inference_visitor.dart:10214:5)
#5      ObjectPattern.acceptPattern1 (package:front_end/src/fasta/kernel/internal_ast.dart:4053:15)
#6      InferenceVisitorImpl.dispatchPattern (package:front_end/src/fasta/type_inference/inference_visitor.dart:9484:12)
#7      TypeAnalyzer.analyzeSwitchStatement (package:_fe_analyzer_shared/src/type_inference/type_analyzer.dart:1637:11)
#8      InferenceVisitorImpl.visitPatternSwitchStatement (package:front_end/src/fasta/type_inference/inference_visitor.dart:8205:9)
#9      PatternSwitchStatement.acceptInference (package:front_end/src/fasta/kernel/internal_ast.dart:464:20)
#10     InferenceVisitorImpl.inferStatement (package:front_end/src/fasta/type_inference/inference_visitor.dart:240:26)
#11     InferenceVisitorImpl.visitLabeledStatement (package:front_end/src/fasta/type_inference/inference_visitor.dart:2016:43)
#12     LabeledStatement.accept (package:kernel/ast.dart:9965:43)
#13     InferenceVisitorImpl.inferStatement (package:front_end/src/fasta/type_inference/inference_visitor.dart:242:26)
#14     InferenceVisitorImpl._visitStatements (package:front_end/src/fasta/type_inference/inference_visitor.dart:852:50)
#15     InferenceVisitorImpl.visitBlock (package:front_end/src/fasta/type_inference/inference_visitor.dart:873:31)
#16     Block.accept (package:kernel/ast.dart:9755:43)
#17     InferenceVisitorImpl.inferStatement (package:front_end/src/fasta/type_inference/inference_visitor.dart:242:26)
#18     TypeInferrerImpl.inferFunctionBody (package:front_end/src/fasta/type_inference/type_inferrer.dart:196:17)
#19     BodyBuilder.finishFunction (package:front_end/src/fasta/kernel/body_builder.dart:1344:43)
#20     DietListener.buildFunctionBody (package:front_end/src/fasta/source/diet_listener.dart:1123:19)
#21     DietListener.endTopLevelMethod (package:front_end/src/fasta/source/diet_listener.dart:376:5)
#22     Parser.parseTopLevelMethod (package:_fe_analyzer_shared/src/parser/parser_impl.dart:3684:14)
#23     Parser.parseTopLevelMemberImpl (package:_fe_analyzer_shared/src/parser/parser_impl.dart:3426:14)
#24     Parser.parseTopLevelDeclarationImpl (package:_fe_analyzer_shared/src/parser/parser_impl.dart:608:14)
#25     Parser.parseUnit (package:_fe_analyzer_shared/src/parser/parser_impl.dart:405:15)
#26     SourceLoader.buildBody (package:front_end/src/fasta/source/source_loader.dart:1267:12)
<asynchronous suspension>
#27     SourceLoader.buildBodies (package:front_end/src/fasta/source/source_loader.dart:676:7)
<asynchronous suspension>
#28     KernelTarget.buildComponent.<anonymous closure> (package:front_end/src/fasta/kernel/kernel_target.dart:611:7)
<asynchronous suspension>
#29     withCrashReporting (package:front_end/src/fasta/crash.dart:136:12)
<asynchronous suspension>
#30     _buildInternal (package:front_end/src/kernel_generator_impl.dart:206:19)
<asynchronous suspension>
#31     withCrashReporting (package:front_end/src/fasta/crash.dart:136:12)
<asynchronous suspension>
#32     generateKernel.<anonymous closure> (package:front_end/src/kernel_generator_impl.dart:48:12)
<asynchronous suspension>
#33     generateKernel (package:front_end/src/kernel_generator_impl.dart:47:10)
<asynchronous suspension>
#34     kernelForModule (package:front_end/src/api_prototype/kernel_generator.dart:100:11)
<asynchronous suspension>
#35     SingleShotCompilerWrapper.compileInternal (file:///b/s/w/ir/cache/builder/sdk/pkg/vm/bin/kernel_service.dart:407:11)
<asynchronous suspension>
#36     Compiler.compile.<anonymous closure> (file:///b/s/w/ir/cache/builder/sdk/pkg/vm/bin/kernel_service.dart:215:45)
<asynchronous suspension>
#37     _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/wildcards_A03_t01

@johnniwinther @chloestefantsova