Minor changes that allow opt-stats.py to support both Python 2 and 3.
In addition to the same dictionary iterator changes that were necessary
in https://reviews.llvm.org/D34564, this diff also:
- Explcitly converts strings to bytes when reading from and writing to stdin and stdout.
- No longer uses dictionaries as a sort key for optimization remarks. Dictionary sort order in Python 2 is pretty esoteric anyway, so it's not clear that the additional sorting had a benefit for end users (for details, https://stackoverflow.com/a/3484456/679254 is a good resource on Python 2 dictionary sort order).
The idea for sticking r.dict at the end was to have a deterministic index page. This allows diffing the before and after html directories to make sure a change is in fact NFC.
Is dict no longer available in Python3?