[tfa] Guard against recursive summary creation

TEST=ci
Issue: #57084
Change-Id: Icacf44847cf5f53c256c62390c4c9ddfc0b80646
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/395400
Auto-Submit: Alexander Markov <[email protected]>
Reviewed-by: Slava Egorov <[email protected]>
Commit-Queue: Alexander Markov <[email protected]>

Author: alexmarkov

pkg/vm/lib/transformations/type_flow/summary_collector.dart

@@ -628,6 +628,9 @@ class SummaryCollector extends RecursiveResultVisitor<TypeExpr?> {
       summaryName += '::${localFunctionName(localFunction)}';
     }
     debugPrint("===== $summaryName =====");
+    if (_enclosingMember != null) {
+      throw 'Unable to create summary recursively, previous: $_enclosingMember, current: $summaryName';
+    }
     assert(!member.isAbstract);
     _enclosingMember = member;
 
@@ -2926,11 +2929,13 @@ class ConstantAllocationCollector implements ConstantVisitor<Type> {
     for (int i = 0; i < constant.positional.length; ++i) {
       final Field f = epl.getRecordPositionalField(recordShape, i);
       final Type value = typeFor(constant.positional[i]);
+      assert(!f.isCovariantByClass);
       epl.addFieldUsedInConstant(f, receiver, value);
     }
     constant.named.forEach((String fieldName, Constant fieldValue) {
       final Field f = epl.getRecordNamedField(recordShape, fieldName);
       final Type value = typeFor(fieldValue);
+      assert(!f.isCovariantByClass);
       epl.addFieldUsedInConstant(f, receiver, value);
     });
     return receiver;
@@ -2941,6 +2946,7 @@ class ConstantAllocationCollector implements ConstantVisitor<Type> {
     final resultClass = summaryCollector._entryPointsListener
         .addAllocatedClass(constant.classNode);
     constant.fieldValues.forEach((Reference fieldReference, Constant value) {
+      assert(!fieldReference.asField.isCovariantByClass);
       summaryCollector._entryPointsListener.addFieldUsedInConstant(
           fieldReference.asField, resultClass, typeFor(value));
     });