[Bug go/83314] gccgo: Compiled binaries panic with "mmap errno 9" on m68k

["jrtc27 at jrtc27 dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83314

--- Comment #5 from James Clarke <jrtc27 at jrtc27 dot com> ---
(In reply to John Paul Adrian Glaubitz from comment #4)
> Ok, I should have actually tested this on real hardware right away.
> 
> Here's on my Amiga 4000:
> 
> root@elgar:~> ./hello 
> 5662
> fatal error: memstats.heap_live not aligned to 8 bytes

heap_live is a uint64, which is only 2-byte aligned on m68k. Either m68k needs
to force stronger alignment here, or the assertion needs dropping for m68k.

> 
> goroutine 16 [running, locked to thread]:
> runtime.dopanic
>         ../../../src/libgo/go/runtime/panic.go:832
> runtime.throw
>         ../../../src/libgo/go/runtime/panic.go:758
> futexwakeup addr=0xc111aa0e returned -1

Futexes must always be 4-byte aligned (kernel requirement), but on m68k ints
only need 2-byte alignment.

> fatal error: unexpected signal during runtime execution
> panic during panic
> [signal SIGSEGV: segmentation violation code=1 addr=4102 pc=3233247334]
> futexwakeup addr=0xc111aa0e returned -1
> fatal error: unexpected signal during runtime execution
> stack trace unavailable
> root@elgar:~>
> 
> On a sidenote: That's probably the first time Go is running on an Amiga!