[PATCH][AArch64] Handle aliases of conditional branches without b.pred form.

[Tim Northover]

> I discussed this with the AArch64 architects, and they stated that all
> assemblers should also accept the b.pred syntax without the dot.
> The syntax without the dot has recently been added to the list of
> pseudo-instructions/alternative syntaxes that should be accepted
> by all assemblers.

Wonderful. Oh well, thanks for the clarification Kristof. The patch
itself looks reasonable to me.

Tim.