Infinity loop/block when a MemberName is used with isExtension=true and isExtension=false

[hfhbd]

Describe the bug
Calling toString/CodeWriter.withCollectedImports and wrong MemberName causes some internal infinity loop without any hints what's wrong and why the execution blocks.

To Reproduce

@Test
fun infinityLoop() {
  val file = FileSpec.builder("foo.bar", "Foo")
  val function = FunSpec.builder("Bar")

  function.addCode(
    "%M%M",
    MemberName("foo.bar.baz", "a"),
    MemberName("foo.bar.baz", "a", isExtension = true),
  )

  file.addFunction(function.build())
  val fileSpec = file.build()
  assertEquals("", fileSpec.toString())
}

Expected behavior
A exception instead stopping the execution.

Additional context