Duplicate 'inline' declarations

[slburson]

In at least one place (lastcons/head/tail) I put a second inline declaration after the defuns it applies to, in addition to the one that precedes them. My recollection is that there are implementations that don't honor the declaration unless it follows the defun, although the more common behavior is the other way around. Alas, I don't recall which implementations want it which way. To top it off, at least one implementation (SBCL?) that wants the declaration first will issue a style warning when it finds another one later.

So the tasks here are:

• test the various implementations to see which order they accept • define features inline-before-defun and inline-after-defun which are set appropriately • make sure all inline declarations appear both before and after their defuns, with the appropriate conditionalization in each case • consider recommending to implementors that, given the standard's vagueness on this point, implementations should accept either order without complaint