This diff updates the debugger to be able to debug async functions again, after the most excellent optimizations introduced in D946914. Minor updates to be able to identify an async func outside of the emitter, and minor adjustments to get breakpoints on async function names working again. Async stacks were fine, the test just needed to be updated. Stepping over await/yield used to decode the instruction stream around OpContSuspend to determine where execution would continue, but that was annoying and brittle. I recently gave c_Continuation the ability to predict its next execution offset, so I enhanced that a bit and switched to using that, so the debugger no longer cares about the codegen around OpContSuspend and doesn't care about anything around OpCreateAsync. This fixes stepping over suspends within a continuation. To get across the first await, we now notice a OpCreateAsync, step over that operation, then grab the c_Continuation off the top of the operand stack and ask it where the heck it's going.
Reviewed By: @hermanventer
Differential Revision: D965577
Setting a breakpoint on a generator would work, but it would set it on the function which simply returns the continuation. That's not super-useful, and the intention is to set it on the beginning of the generator. Changed to do that. This change also gets the $continuation off of the function name when printing it at breakpoints.
Differential Revision: D931931
Jordan DeLong