Not detecting re-generated file

[thoni56]

It seems that a re-generated file, such as a .c-file generated from a .y, is not detected and does not trigger an update of the tags for that file. At least the navigation with / does not match the actual positions.

Note that this is just a guess about the cause of some symptoms I'm seeing when navigating in a C/Yacc project where the build automatically re-generates the .c-file if required.