Crash due to stack overflow caused by null sanitizer

Crashes were observed on a proprietary app in a build where the null sanitizer was enabled. This check causes a huge ~7x increase in code, and also in stack usage as each pointer is stored and retrieved from a local on the stack as part of an is-null check. This increases stack space usage on the DR stack (primary and signal both), and the app stack too when using the app start/stop interface.

We can probably disable the null sanitizer for the functions that are problematic (e.g. `dump_global_stats` which has a lot of pointer derefereces (9 for each stat), which leads to a huge 127KB frame.