Lower reverse shuffles to a vrev64 and a vext instruction instead of the default
legalization of storing and loading to the stack. This is important because we
generate reverse shuffles in the loop vectorizer when we reverse store to an
array.
uint8_t Arr[N];
for (i = 0; i < N; ++i)
Arr[N - i - 1] = ...
radar://13171760
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174929 91177308-0d34-0410-b5e6-96231b3b80d8
d9316dacf5