fixes #9829 (#11849)

tests/vm/tmaxloopiterations.nim

@@ -0,0 +1,15 @@
+discard """
+errormsg: "interpretation requires too many iterations; if you are sure this is not a bug in your code edit compiler/vmdef.MaxLoopIterations and rebuild the compiler"
+"""
+
+# issue #9829
+
+macro foo(): untyped  =
+  let lines = ["123", "5423"]
+  var idx = 0
+  while idx < lines.len():
+    if lines[idx].len() < 1:
+      inc(idx)
+      continue
+
+foo()