tree a55e2bf0d5925c97010fd9bdb2afb1dc3bdcb9fc
parent 02a472a0dbb7d21810ef2c56626eba2113e5a049
author Jukka Lehtosalo <jukka.lehtosalo@iki.fi> 1752321292 +0100
committer Jukka Lehtosalo <jukka.lehtosalo@iki.fi> 1752673744 +0100

Micro-optimization: Make ArgKind a regular class instead of enum

Mypyc doesn't generate very efficient code for enums, so switch to a
regular class. We can later revert the change if/when we can improve
enum support in mypyc.

Operations related to ArgKind were pretty prominent in the op trace
log (#19457).

By itself this improves performance by ~1.7%, based on
`perf_compare.py`, which is significant:
```
master                    4.168s (0.0%) | stdev 0.037s
HEAD                      4.098s (-1.7%) | stdev 0.028s
```

This is a part of a set of micro-optimizations that improve self check
performance by ~5.5%.