[DeLICM] Add nomap regressions tests. NFC.

These verify that some scalars are not mapped because it would be
incorrect to do so.

For these check we verify that no transformation has been executed from
output of the pass's '-analyze'. Adding optimization remarks is not useful
as it would result in too many messages, even repeated ones. I avoided
checking the '-debug-only=polly-delicm' output which is an antipattern.

llvm-svn: 296348