If we have +sme but not +sve, we would not set vscale_range on
functions. It should be valid to apply it with the same range with just
+sme, which can help mitigate some performance regressions in cases such
as scalable vector bitcasts (https://godbolt.org/z/exhe4jd8d).
(cherry picked from commit 9f1c825fb62319b94ac9604f733afd59e9eb461b)
d185bd94ff