Fix edge case in switch with single else

ir_gen_switch_expr doesn't set the switch_br field at all if there are
zero cases, detect this situation and handle it gracefully.

Closes #4322
59bc1d2721LemonBoy committed on 1/29/2020, 9:05:14 PM· committed by Andrew Kelleyparent4fad162
2 files changedLine totals unavailable