Some uses of the preprocessor can result in multiple target regions on the

same line. Cases such as those in the associated lit tests, can now be
supported.

This adds a 'Count' field to TargetRegionEntryInfo to differentiate
regions with the same source position.

The OffloadEntriesInfoManager routines are updated to maintain a count of
regions seen at a location. The registration of regions proceeds that same as
before, but now the next available count is always determined and used in the
offload entry.

Fixes: https://github.com/llvm/llvm-project/issues/52707

Differential Revision: https://reviews.llvm.org/D134816