Add cycle-checking for `JsrValue` constructor (to avoid SOE)

[dantesun]

I am sorry but I can't provide more information. My guess this error happend when using JSON.asString to serialize a JsrValue object. The jackson-jr version is 2.11.2.

java.lang.StackOverflowError
	at com.fasterxml.jackson.jr.private_.json.WriterBasedJsonGenerator.writeStartObject(WriterBasedJsonGenerator.java:296)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter.writeBeanValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.BeanWriter.writeValue(BeanWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter._writeValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter.writeBeanValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.BeanWriter.writeValue(BeanWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter._writeValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter.writeBeanValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.BeanWriter.writeValue(BeanWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter._writeValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter.writeBeanValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.BeanWriter.writeValue(BeanWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter._writeValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter.writeBeanValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.BeanWriter.writeValue(BeanWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter._writeValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter.writeBeanValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.BeanWriter.writeValue(BeanWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter._writeValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter.writeBeanValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.BeanWriter.writeValue(BeanWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter._writeValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter.writeBeanValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.BeanWriter.writeValue(BeanWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter._writeValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter.writeBeanValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.BeanWriter.writeValue(BeanWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter._writeValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter.writeBeanValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.BeanWriter.writeValue(BeanWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter._writeValue(JSONWriter.java)
	at com.fasterxml.jackson.jr.ob.impl.JSONWriter.writeBeanValue(JSONWriter.java)