profile if profiling enabled even if instrumentation disabled

Profiling doesn't currently work if instrumentation is disabled, which isn't what I intended when I recently landed support for disabling instrumentation. Instrumentation clutters the console and may distort the profile, so it should possible to profile without instrumentation.

Here's the minimal fix. Long-term we may want to separate these facilities in the code, so it's harder for a change in one to break the other. But that would be a bigger change.