Keep lines above comments in enums

Src/CSharpier.Tests/FormattingTests/TestFiles/EnumDeclarationComments.cst

@@ -0,0 +1,15 @@
+public enum SubCode
+{
+    First,
+
+    // keep line
+    BasicComment,
+
+    /* keep line */
+    MultiLineComment,
+
+    /// keep line
+    XmlComment,
+
+    DoNotKeepLine
+}

Src/CSharpier.Tests/FormattingTests/TestFiles/EnumDeclarationComments.expected.cst

@@ -0,0 +1,14 @@
+public enum SubCode
+{
+    First,
+
+    // keep line
+    BasicComment,
+
+    /* keep line */
+    MultiLineComment,
+
+    /// keep line
+    XmlComment,
+    DoNotKeepLine
+}

Src/CSharpier/DocPrinter/PropagateBreaks.cs

@@ -2,7 +2,11 @@ namespace CSharpier.DocPrinter;
 
 internal static class PropagateBreaks
 {
-    private static readonly Doc TraverseDocOnExitStackMarker = new();
+    private class MarkerDoc : Doc
+    {
+    }
+
+    private static readonly MarkerDoc TraverseDocOnExitStackMarker = new();
 
     public static void RunOn(Doc document)
     {

Src/CSharpier/DocTypes/Doc.cs

@@ -1,6 +1,6 @@
 namespace CSharpier.DocTypes;
 
-internal class Doc
+internal abstract class Doc
 {
     public static implicit operator Doc(string value)
     {

Src/CSharpier/SyntaxPrinter/SyntaxNodePrinters/EnumMemberDeclaration.cs

@@ -6,6 +6,17 @@ public static Doc Print(EnumMemberDeclarationSyntax node)
     {
         var docs = new List<Doc>
         {
+            node.GetLeadingTrivia()
+            .Any(
+                o =>
+                    o.Kind()
+                        is SyntaxKind.SingleLineCommentTrivia
+                            or SyntaxKind.MultiLineCommentTrivia
+                            or SyntaxKind.SingleLineDocumentationCommentTrivia
+                            or SyntaxKind.MultiLineDocumentationCommentTrivia
+            )
+                ? ExtraNewLines.Print(node)
+                : Doc.Null,
             AttributeLists.Print(node, node.AttributeLists),
             Modifiers.Print(node.Modifiers),
             Token.Print(node.Identifier)