[dev.typeparams] cmd/compile: do not skip TestUnifiedCompare in short mode
[dev.typeparams] cmd/compile: do not skip TestUnifiedCompare in short mode

Instead, just testing the runtime package in short mode instead of std.
So trybot can help catching any mistake earlier.

Change-Id: I5bc859a59afa13a10d436a798258ac154c7d27b2
Reviewed-on: https://go-review.googlesource.com/c/go/+/330836
Trust: Cuong Manh Le <54b4457f1dff6823379654eb5867596497ba782f@gmail.com>
Run-TryBot: Cuong Manh Le <54b4457f1dff6823379654eb5867596497ba782f@gmail.com>
TryBot-Result: Go Bot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Matthew Dempsky <e56ac2c500064424afac424d4b5e53bd0570a731@google.com>

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