When compiling code and linking blocks, disable all signals then
reenable once back in the dispatcher.
This adds 15-40 microseconds on to each of these steps and some
additional branching overhead.
This is a problem where our allocator is not reentrant safe and when
receiving a signal we need to jump to a new code region and compile.
Depending on the mutexes that are currently live, we will just stall out
forever.
This is /very/ commonly picked up when attempting to run pressure-vessel
Ryan Houdek
e1604fb32f