Removed nan & infinity variables

[architsinghal-mriirs]

Issue #4739 Hi @kripken I've made some changes as per the suggestions. I searched for nan in the entire codebase and found alot of instances of the same code. I've removed the code from few other files. Please review and let me know if this is this is correct.

Thanks and Regards Archit Singhal

[kripken]

In general I think this might be good, but let's get the test failures fixed first. Please run ./auto_update_tests.py wasm2js and commit those changes.