This change fixes the edge case where a negative sleep time is provided.
When this happens, the call now returns immediately (as specified by the docs for time.Sleep).
This commit implements various process related functions like
os.Getuid() and os.Getpid(). It also implements or improves this support
in the syscall package if it isn't available yet.
This improves compatibility between the regular browser target
(-target=wasm) and the WASI target (-target=wasi). Specifically, it
allows running WASI tests like this:
tinygo test -target=wasi encoding/base32
strings.IndexByte was implemented in the runtime up to Go 1.11. It is
implemented using a direct call to internal/bytealg.IndexByte since Go
1.12.
Make sure we remain compatible with both.
