When value of immediate in `mips.nori.b` is 255 (which has all ones in
binary form as 8bit integer) DAGCombiner and Legalizer would fall in an
infinite loop. DAGCombiner would try to simplify `or %value, -1` by
turning `%value` into UNDEF. Legalizer will turn it back into `Constant<0>`
which would then be again turned into UNDEF by DAGCombiner. To avoid this
loop we make UNDEF legal for MSA int types on Mips.
Patch by Mirko Brkusanin.
Differential Revision: https://reviews.llvm.org/D67280
llvm-svn: 371607
d811d9115b