Length script property for List View didn't include a name for the property so it defaulted to using the script as the property name (#4437)

src/System.Management.Automation/commands/utility/FormatAndOutput/common/DefaultFormatters/FileSystem_format_ps1xml.cs

@@ -74,7 +74,7 @@ return $_.Length";
                     .GroupByProperty("PSParentPath", customControl: sharedControls[0])
                     .StartEntry(entrySelectedByType: new[] { "System.IO.FileInfo" })
                         .AddItemProperty(@"Name")
-                        .AddItemScriptBlock(LengthScriptBlock)
+                        .AddItemScriptBlock(LengthScriptBlock, label: "Length")
                         .AddItemProperty(@"CreationTime")
                         .AddItemProperty(@"LastWriteTime")
                         .AddItemProperty(@"LastAccessTime")

test/powershell/Modules/Microsoft.PowerShell.Utility/Format-List.Tests.ps1

@@ -149,5 +149,12 @@ Describe "Format-List DRT basic functionality" -Tags "CI" {
 		$result | Should Match "Length : 2"
 		$result | Should Match "Name   : name3"
 		$result | Should Match "Length : 3"
-	}
+    }
+
+    It "Format-List with FileInfo should work" {
+        $null = New-Item $testdrive\test.txt -ItemType File -Value "hello" -Force
+        $result = Get-ChildItem -File $testdrive\test.txt | Format-List | Out-String
+        $result | Should Match "Name\s*:\s*test.txt"
+        $result | Should Match "Length\s*:\s*5"
+    }
 }