internal/origin: TestMaxUint16 can be replaced with a compile-time assertion

[dolmen]

TestMaxUint16 can be replaced by:

// If this doesn't compile we have a mismatch of maxUint16 and math.MaxUint16
var _ = [1]int{}[maxUint16-math.MaxUint16]

Explanation: the difference between maxUint16 and math.MaxUint16 must be 0.

[jub0bs]

Promising! I'll try that. Not that the test in question is prohibitively slow (far from it), but if more things can be checked at compile time, I'm all for it.