Improved error handling for Indexer
Improved error handling for MatchLocator
Bounds checking for mappings in IncudeEntry
Improved error handling for Merge operations
Source file name fitering for recreating an already existing index
Further enhancements for PR 39580. If the icons are
different (ie debug and release) then the executables
show up as different entries when they should show up
as the same with different "qualifiers"