Revert "cmSourceFileLocation: Normalize compared directories."

This reverts commit e081db393891a75aeaf84adfc663e352622d3e93.
cmSourceFileLocation: Remove unused Update method.

The string overload is never called. This allows the removal of
the unused UpdateDirectory method.
cmSourceFileLocation: Collapse full path for directory comparisons.
Change the diagnostic message.
Merge topic 'target-sources-refactor' into next

dd96bd65 Change the diagnostic message.
a9143928 cmSourceFileLocation: Collapse full path for directory comparisons.
c205e44f cmSourceFileLocation: Remove unused Update method.
3190bfbf Revert "cmSourceFileLocation: Normalize compared directories."