Carbon crash

[pieter-bos]

Hi! I managed to crash carbon with this input:

method m()
{
  label start
  goto start

  while(true) {  }
}

Which reports:

carbon 1.0
Exception in thread "main" java.lang.RuntimeException: While loop is not a loop head
	at scala.sys.package$.error(package.scala:27)
	at viper.carbon.modules.impls.DefaultLoopModule.getWhileInformation(DefaultLoopModule.scala:416)
	at viper.carbon.modules.impls.DefaultLoopModule.handleWhile(DefaultLoopModule.scala:426)
	at viper.carbon.modules.impls.DefaultLoopModule.$anonfun$handleStmtLoopDetector$1(DefaultLoopModule.scala:484)
(...)