Don't clobber the position of cloned nodes

Author: amcasey

src/services/utilities.ts

@@ -1349,15 +1349,16 @@ namespace ts {
         const visited = visitEachChild(node, getSynthesizedDeepClone, nullTransformationContext);
         if (visited === node) {
             // This only happens for leaf nodes - internal nodes always see their children change.
-            return getSynthesizedClone(node);
+            const clone = getSynthesizedClone(node);
+            clone.pos = node.pos;
+            clone.end = node.end;
+            return clone;
         }
 
         // PERF: As an optimization, rather than calling getSynthesizedClone, we'll update
         // the new node created by visitEachChild with the extra changes getSynthesizedClone
         // would have made.
 
-        visited.pos = -1;
-        visited.end = -1;
         visited.parent = undefined;
 
         return visited;