run-tests: also follow symlink when update PATH with 'run-tests.py' dir
I'm using 'run-tests.py' from my '$PATH' and use a symlink to get 'run-tests.py'
to in that '$PATH'. There is a handful of test helpers (like f) that needs to be
in the '$PATH' for the test to run, and they are expected to live next to the
'run-tests.py' binary. Using a symlink confuses this logic, so we add to the
'$PATH' both the 'run-tests.py' executable directory, and the actual file
location direction.
$ hg init
$ echo 123 > a
$ hg add a
$ hg commit -m "first" a
$ mkdir sub
$ echo 321 > sub/b
$ hg add sub/b
$ hg commit -m "second" sub/b
$ cat sub/b
321
$ hg co 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cat sub/b 2>/dev/null || echo "sub/b not present"
sub/b not present
$ test -d sub || echo "sub not present"
sub not present