RFR(M): 8213528: fp registers should not need to be saved around a CallLeafNoFP

[Roland Westrelin]

>> Indeed there's no more use of IdealKit::make_leaf_call_no_fp() and NO_FP
>> after my change. I left both there because I suppose some existing calls
>> to CallLeaf could be turned into the "new" CallLeafNoFP and so this code
>> might be needed in the future but I can remove it if you like.
>
> I supposed we'd use it from Shenandoah, right?

That stuff is for parse time. We emit our CallLeafNoFP after parse
time. So we don't need that stuff.

Roland.