Warn / throw for incorrectly formed patches

[nosoop]

Trying to think of the best way to deal with false positives on applying patches.

• warning at config parse time doesn't really make sense, as it would be an annoyance for patches that aren't intentionally supported (e.g. unsupported platforms)
• if we throw an exception at runtime, we need to support pre-flight checks — we do have MemoryPatch.Validate but it's vague

A zero-length patch should always fail at runtime (since there's nothing to patch). Maybe add an optional enum by-ref param to MemoryPatch.Validate indicating the reason that the validation failed?