Many tests failed in gojs due to needing to be resolved against the CWD,
which is atypically stored host side. This fixes that and renames the
"exit" scope to "proc" so we can use it for other proc concerns besides
exit.
This reduces known failures on GOOS=js from 23 to 14:
```bash
$ wazero run -mount=/usr/local/go/src/os:/:ro -mount=/tmp:/tmp -mount=/etc:/etc:ro -mount=/usr:/usr:ro -mount=/dev:/dev:ro os.wasm |grep '^--- FAIL'|wc -l
14
```
See #1222
Signed-off-by: Adrian Cole <adrian@tetrate.io>
6243091dc2