[ARM] Expand ROTL and ROTR of vector value types

Summary: After D13851 landed, we saw backend crashes when compiling the reduced test case included in this patch. The right fix seems to be to allow these vector types for expansion in instruction selection.

Reviewers: rengolin, t.p.northover

Subscribers: RKSimon, t.p.northover, aemerson, llvm-commits, rengolin

Differential Revision: http://reviews.llvm.org/D14082

llvm-svn: 251401