See: https://github.com/tinygo-org/tinygo/issues/4314
The os package isn't particularly useful on wasm-unknown, but just like
on baremetal systems it's imported by a lot of packages so it should at
least be possible to import this package.
Do it all at once in preparation for Go 1.18 support.
To make this commit, I've simply modified the `fmt-check` Makefile
target to rewrite files instead of listing the differences. So this is a
fully mechanical change, it should not have introduced any errors.
This generally means that code size is reduced, especially when the os
package is not imported.
Specifically:
- On Linux (which currently statically links musl), it avoids calling
malloc, which avoids including the musl C heap for small programs
saving around 1.6kB.
- On WASI, it avoids initializing the args slice when the os package
is not used. This reduces binary size by around 1kB.
This is mainly useful to be able to run `tinygo test`, for example:
tinygo test -target=cortex-m-qemu -v math
This is not currently supported, but will be in the future.