Sure, but I had to look:
Tier1: Windows x64/i686, Linux x64/ARM gcc, Darwin/ARM
Tier2: Linux x64/ARM w/ clang, Windows ARM, WASM, Darwin/x64
Tier3 is a pretty low support level, but tiers 1 and 2 is a pretty short list of major commercial platforms. Also even for developers to fix, availability of e.g. RiscV machines in the cloud to reproduce and fix on is still somewhat limited.
Windows i686, tier 1, what? I’ll do some digging when I’m home but I feel the sudden need to understand this.
Oh, wow
https://learn.microsoft.com/en-us/lifecycle/products/windows...
Interestingly embedded 32 bit Linux is not tier 1 or 2 though :)