[Bug gcov-profile/94928] Doc comments in gcov-io.h do not show cwd and unexec blocks in the Notes file format

[myron.walker at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94928

--- Comment #12 from Myron Walker <myron.walker at gmail dot com> ---
What would be helpful then is if gcno, gcda and source files could all have
separate root file system prefixes.