fixes new liftLocals pass

compiler/liftlocals.nim

@@ -52,17 +52,19 @@ proc lookupParam(params, dest: PNode): PSym =
     if params[i].kind == nkSym and params[i].sym.name.id == dest.ident.id:
       return params[i].sym
 
-proc liftLocalsIfRequested*(prc: PSym) =
+proc liftLocalsIfRequested*(prc: PSym; n: PNode): PNode =
   let liftDest = getPragmaVal(prc.ast, wLiftLocals)
-  if liftDest == nil: return
+  if liftDest == nil: return n
   let partialParam = lookupParam(prc.typ.n, liftDest)
   if partialParam.isNil:
     localError(liftDest.info, "'$1' is not a parameter of '$2'" %
               [$liftDest, prc.name.s])
-    return
+    return n
   let objType = partialParam.typ.skipTypes(abstractPtrs)
   if objType.kind != tyObject or tfPartial notin objType.flags:
     localError(liftDest.info, "parameter '$1' is not a pointer to a partial object" % $liftDest)
-    return
+    return n
   var c = Ctx(partialParam: partialParam, objType: objType)
-  liftLocals(prc.ast, bodyPos, c)
+  let w = newTree(nkStmtList, n)
+  liftLocals(w, 0, c)
+  result = w[0]