Improve DebugInfo/strip-loop-metadata.ll test

This wasn't covering for the case where you have multiple latches and hence
the use of the same loop-id which needs to be mapped to the same loop-id.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@299237 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed