Hmmm, "go install" doesn't like the "-ftest" file, remove for now

$ go install github.com/benhoyt/goawk@latest
go: downloading github.com/benhoyt/goawk v1.8.0
go install: github.com/benhoyt/goawk@latest: github.com/benhoyt/goawk@v1.8.0: verifying module: github.com/benhoyt/goawk@v1.8.0: reading https://sum.golang.org/lookup/github.com/benhoyt/goawk@v1.8.0: 410 Gone
	server response: not found: create zip: -ftest: malformed file path "-ftest": leading dash

Bump up version number for release 1.8.0

remove darwin/386 (no longer supported)

Fix parsing precedence of unary operators, eg: '!seen[$0]++' idiom (b…

…enhoyt#33)

Fix split() to have same behavior for single-char FS

Fix case of empty input line (NF should be 0)

Add script to build cross-platform binaries

Windows, Linux, macOS in 32- and 64-bit variants

Fixes benhoyt#23 (thanks @cup)

Simplify exec calls to use in/out/err fields directly rather than pipe

For example, we don't need to use StdoutPipe with another goroutine
that copies, we can just use Cmd.Stdout directly. Same for Cmd.Stderr
and Cmd.Stdin.

Add unit tests for the above and bump up version (patch).

Add config options for "safe mode" to prevent exec and file reads/writes

This is useful for running scripts from untrusted user input.

Bump up version number for release

Make a[x] array access set the element if not present (per POSIX spec)

This seems very unintuitive to me, but it's very clear in the spec, and
awk/gawk/mawk all do this.

Also fix delarpm2 gawk test as (again per POSIX) "The results of adding
new elements to array within such a for loop are undefined."