reenter

This is called when the invocation for this step had to reify, and now we've finished the actual Avail call and we're attempting to continue where we left off. We have to check the returned value and either capture it on the stack or invoke the result check failure function.

Note that at this time, only registers0 has been set up, so if this reentry succeeds (i.e., the return value satisfies the expectedType), we need to transfer the top continuation's slots into the registers array and pop that continuation off the call stack.

Also, if the current chunk has become invalid, we will alter the interpreter's current chunk to the unoptimizedChunk to indicate this, allowing the (Kotlin) caller to immediately return to the interpreter loop for L1 interpretation.