stringStream has some issues:

- In dynamic mode (which is 90% of use cases) it has no size cap in dynamic mode. Hence faulty - or just very chatty - printing code can use large amounts of memory (this is similar to https://bugs.openjdk.java.net/browse/JDK-8220394)

- Since 8224193, stringStream uses no resource area anymore as backing buffer but C-heap. A large amount of stringStream uses is for very short output - to reduce malloc calls, lets use a small internal buffer.