QFileSystemWatcher can't watch paths with some Unicode characters on macOS

The attached program will try to create a file given as argv[1] and watch for modifications on it, then it will open it in write mode and wait for qt's notification that the file is modified.

How to reproduce:

• mkdir /tmp/cafe
• ./t /tmp/cafe/foo
• mkdir /tmp/café
• ./t /tmp/café/foo

In both cases addPath will return success, but in the latter, we are never notified and the program waits forever.

The bug occurs only if the watched file is in a path that contains some unicode characters, not when the file name itself contains them.

About the unicode characters, it seems that the bug only manifest with composed unicode characters, so with words like "café" (I heard the é is a ´ and a 'e' on mac), korean characters, but it works with japanese characters like "日本".