[ARM][MVE] Enable tail-predication by default

Authored by SjoerdMeijer on Sep 28 2020, 6:01 AM.


[ARM][MVE] Enable tail-predication by default

We have been running tests/benchmarks downstream with tail-predication enabled
for some time now and this behaves as expected: we are not aware of any
correctness issues, and this performs better across the board than with
tail-predication disabled. Time to flip the switch!

Differential Revision: https://reviews.llvm.org/D88093