[llvm-dev] Python 2 compatibility for utility scripts

[Fangrui Song via llvm-dev]

https://reviews.llvm.org/D71565 intends to update llvm/utils/update_cc_test_checks.py to work with Python 2.

In the original review, I suggested that we don't add Python 2
compatibility for new features because Python 2.7 is retiring and some
Linux distributions are even deprecating/removing Python 2 support. My
feeling is:

If some utilities do not support Python 2, we should probably not bother
making them Python 2 compatible. Maintaining Python 2/3 compatibility
may not worth the efforts. "utilities" include some command line tools
under llvm/utils, which are not part of instructure like lit. What do
people think?

BTW, what's the Python 3 support status of build bots? Are there any
running Python 3?