Fix #6518: Add missing case for While

Author: nicolasstucki

library/src/scala/tasty/reflect/TreeUtils.scala

@@ -46,6 +46,8 @@ trait TreeUtils
           foldTree(foldTrees(x, stats), expr)
         case If(cond, thenp, elsep) =>
           foldTree(foldTree(foldTree(x, cond), thenp), elsep)
+        case While(cond, body) =>
+          foldTree(foldTree(x, cond), body)
         case Lambda(meth, tpt) =>
           val a = foldTree(x, meth)
           tpt.fold(a)(b => foldTree(a, b))

tests/run-macros/tasty-extractors-3/quoted_2.scala

@@ -10,6 +10,7 @@ object Test {
       def f2[T >: Int <: Int](): T = ???
       class Foo { type X }
       val foo = new Foo { type X = String }
+      while (true) println()
     }
   }
 }