Add field names: whenExpr to Clause, isMutable to Field (#6308)

src/fsharp/ast.fs

@@ -1147,7 +1147,7 @@ and
 and
     [<NoEquality; NoComparison>]
     SynMatchClause =
-    | Clause of SynPat * SynExpr option *  SynExpr * range:range * SequencePointInfoForTarget
+    | Clause of SynPat * whenExpr: SynExpr option * SynExpr * range:range * SequencePointInfoForTarget
 
     member this.RangeOfGuardAndRhs =
         match this with
@@ -1395,7 +1395,7 @@ and
     [<NoEquality; NoComparison>]
     /// The untyped, unchecked syntax tree for a field declaration in a record or class
     SynField =
-    | Field of attrs:SynAttributes * isStatic:bool * Ident option * SynType * bool * xmlDoc:PreXmlDoc * accessibility:SynAccess option * range:range
+    | Field of attrs:SynAttributes * isStatic:bool * Ident option * SynType * isMutable: bool * xmlDoc:PreXmlDoc * accessibility:SynAccess option * range:range
 
 and
     [<NoEquality; NoComparison>]