[LV] Support float and pointer FindLast reductions (#184101)
This duplicates #182313 with some very small modifications on top, as
@dheaton-arm is unable
to finish the PR and I'm unable to push to his branch.
Expands support for the `FindLast` Reccurence Kind to floating-point and
pointer types, thereby
enabling conditional scalar assignment (CSA) for these types.
Originally authored by @dheaton-arm
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Co-authored-by: Damian Heaton <Damian.Heaton@arm.com>