Please expose XML_SetBillionLaughsAttackProtectionActivationThreshold() functionality

[dlangille]

Hello,

I have a use case where I'm hitting the Billion Laughs limits with valid (and trusted) files. I was able to find a fix by patching expat. I opened an issue and provided my temp fix. The issue contains a sample function and shows how to reproduce the issue.

Please provide a way for XML-Parser users to invoke the XML_SetBillionLaughsAttackProtectionActivationThreshold function. That would let me set the value at run-time instead of hardcoding a new default-value at build time.

Thank you.