Fix and re-enable test-examples.

These tests have been disabled for a long time, apparently by accident. This
patch restores them, and applies fixes necessary to get them working. Notably:

- Fix the simulated-runtime-calls example, and correct an ifdef to ensure that
  it builds.
- Enable --trace-* options for test-examples, to match the behaviour of other
  tests.

Change-Id: Iab0034f19ce935ba7237f8546f9c43f8cec13312