This eliminates the 'wasi' build tag in favor of 'GOOS=wasip1', introduced in Go 1.21.
For backwards compatablity, -target=wasi is a synonym for -target=wasip1.
This basically reverts https://github.com/tinygo-org/tinygo/pull/3357
and replaces it with a different mechanism to get to the same goal.
I do not think filtering tags like this is a good idea: it's the wrong
part of the compiler to be concerned with such tags (that part sets
tags, but doesn't modify existing tags). Instead, I've written the
//go:build lines in such a way that it has the same effect: WASI
defaults to leveldb, everything else defaults to fnv, and it's possible
to override the default using build tags.
Damian Gryski
Randy Reddig
Ayke van Laethem
Yurii Soldak