bug#67005: 30.0.50; improve nadivce/comp/trampoline handling

[Stefan Monnier]

> "function" is the function we are redefining and we want to trigger the
> trampoline thing only when that's a C primitive.  Those two conditions
> are equivalent to 'subr-primitive-p'.

Oh, right, because we don't implement that same optimization calls to
native-compiled functions, right?
Shouldn't we implement that optimization for calls to
native-compiled functions, tho?  At least for the case where that
function is defined in the same file as the call?


        Stefan