Problems reported:

parser/error_recovery/issue_46505_prime_4.crash:2:24: Expected a type, but got '>>>'.
  Stream<List<Set<List<>>>>
                       ^^^

parser/error_recovery/issue_46505_prime_4.crash:3:1: Expected an identifier, but got '}'.
}
^

parser/error_recovery/issue_46505_prime_4.crash:2:27: Expected ';' after this.
  Stream<List<Set<List<>>>>
                          ^

beginCompilationUnit(class)
  beginMetadataStar(class)
  endMetadataStar(0)
  beginClassOrMixinOrNamedMixinApplicationPrelude(class)
    handleIdentifier(A, classOrMixinDeclaration)
    handleNoTypeVariables({)
    beginClassDeclaration(class, null, A)
      handleNoType(A)
      handleClassExtends(null, 1)
      handleClassNoWithClause()
      handleClassOrMixinImplements(null, 0)
      handleClassHeader(class, class, null)
      beginClassOrMixinOrExtensionBody(DeclarationKind.Class, {)
        beginMetadataStar(Stream)
        endMetadataStar(0)
        beginMember()
          beginFields(DeclarationKind.Class, null, null, null, null, null, null, {)
            handleIdentifier(Stream, typeReference)
            beginTypeArguments(<)
              handleIdentifier(List, typeReference)
              beginTypeArguments(<)
                handleIdentifier(Set, typeReference)
                beginTypeArguments(<)
                  handleIdentifier(List, typeReference)
                  beginTypeArguments(<)
                    handleRecoverableError(Message[ExpectedType, Expected a type, but got '>>>'., null, {lexeme: >>>}], >>>, >>>)
                    handleIdentifier(, typeReference)
                    handleNoTypeArguments(>>>)
                    handleType(, null)
                  endTypeArguments(1, <, >)
                  handleType(List, null)
                endTypeArguments(1, <, >)
                handleType(Set, null)
              endTypeArguments(1, <, >)
              handleType(List, null)
            endTypeArguments(1, <, >)
            handleType(Stream, null)
            handleRecoverableError(Message[ExpectedIdentifier, Expected an identifier, but got '}'., Try inserting an identifier before '}'., {lexeme: }}], }, })
            handleIdentifier(, fieldDeclaration)
            handleNoFieldInitializer(})
            handleRecoverableError(Message[ExpectedAfterButGot, Expected ';' after this., null, {string: ;}], >, >)
          endClassFields(null, null, null, null, null, null, 1, Stream, ;)
        endMember()
      endClassOrMixinOrExtensionBody(DeclarationKind.Class, 1, {, })
    endClassDeclaration(class, })
  endTopLevelDeclaration()
endCompilationUnit(1, )