Jit: Fix for [Issue 2302318] Crash during spin-on-suspend testing

This was an amusing bug: the test case simulated a daemon by falling
into an empty loop-forever.  The trace selector treats unconditional
branches as NOPs, and proceeded to repeatedly add the same "branch to self"
instruction to the trace until it reached max trace size.  The compiler
got confused, and died.
4 files changed