cmd/compile: clean up C->Go translation artifacts in badtype
cmd/compile: clean up C->Go translation artifacts in badtype

Change-Id: I576a596ed8e9ce14e3750031d0e338e9276eff1e
Reviewed-on: https://go-review.googlesource.com/c/go/+/262537
Trust: Alberto Donizetti <90b16103a35511ced020676f3544f17117fb4c92@gmail.com>
Run-TryBot: Alberto Donizetti <90b16103a35511ced020676f3544f17117fb4c92@gmail.com>
TryBot-Result: Go Bot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Cuong Manh Le <54b4457f1dff6823379654eb5867596497ba782f@gmail.com>
Reviewed-by: Matthew Dempsky <e56ac2c500064424afac424d4b5e53bd0570a731@google.com>

nawawi/go,CAFxX/go,cloudflare/go,cloudflare/go,nawawi/go,nawawi/go,golang/go,CAFxX/go,nawawi/go,CAFxX/go,CAFxX/go,nawawi/go,CAFxX/go,CAFxX/go,golang/go,cloudflare/go,cloudflare/go,cloudflare/go,golang/go,cloudflare/go,golang/go,cloudflare/go,CAFxX/go,golang/go,golang/go,golang/go,nawawi/go,golang/go,nawawi/go,CAFxX/go,nawawi/go,cloudflare/go