pkg/59871: Tailscale on i386 was built with SSE enabled and crashes on hardware without SSE

>Number:         59871
>Category:       pkg
>Synopsis:       Tailscale on i386 was built with SSE enabled and crashes on hardware without SSE
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Dec 31 13:15:00 +0000 2025
>Originator:     Nikola Radojević
>Release:        10.1
>Organization:
/
>Environment:
NetBSD i486-netbsd 10.1 NetBSD 10.1 (GENERIC) #0: Mon Dec 16 13:08:11 UTC 2024  [email protected]:/usr/src/sys/arch/i386/compile/GENERIC i386
>Description:
Tailscale on i386 (which actually targets 486) crashes on my hardware with an "Illegal instruction" exception. When I opened the coredump in gdb, the offending instruction was `xorps  %xmm0,%xmm0`, which a 486 class cpu doesn't have. Go's toolchain does support the option of using softfloats instead, unfortunately not x87.
>How-To-Repeat:
Install tailscale and run tailscaled, you'll get:
```
i486-netbsd$ tailscaled
[1]   Illegal instruction (core dumped) tailscaled
```
>Fix:
The go toolchain should be instruction to use softfloats instead, they don't support x87 and 486 class cpus don't have SSE