Need a FAIL_FAST option for halting a test when an unexpected call occurs.

When any expected call fails, the return values of the remaining calls fall back to their default state (or 0 if not set). Which can be misleading when a successful return code is a zero (i.e. the system assigned default).

This can manifest itself in a seemingly unpredictable way, making tracing the "real" issue difficult (to say the least). For example, when call "n", the unexpected call, ultimately causes the framework to crash because call "n+7" now returns a `NULL` pointer. Therefore, we have almost no way to know which call is actually failing, because we are seeing all the calls "0 - (n+6)" have all returned "success" values then it crashes...

Start by locating the unexpected-call handling and the logic that supplies default return values for subsequent calls. Trace how a failed expected call affects later calls, then verify that a FAIL_FAST option stops execution at the unexpected call and avoids misleading fallback results.

Written by the indexing model from the issue text.