[Patch] to ease debugging of ports utilizing go

Hi,
I recently needed to debug sysutils/docker (with gdb) utilizing the WITH_DEBUG_PORTS variable and I noticed some variables got "optimized out". In the attachment is a patch (diff for Mk/Uses/go.mk) that fixes just that.
The solution is based on the "Introduction" section here: https://go.dev/doc/gdb

Thanks!