[Bug go/86331] the gccgo's "go" tool looks like failing to invoke any sub go command

[ian at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86331

--- Comment #11 from ian at gcc dot gnu.org <ian at gcc dot gnu.org> ---
Author: ian
Date: Mon Jul  2 16:28:43 2018
New Revision: 262313

URL: https://gcc.gnu.org/viewcvs?rev=262313&root=gcc&view=rev
Log:
        PR go/86331
    os: check return value as well as error from waitid

    https://gcc.gnu.org/PR86331 indicates that if a signal handler runs it
    is possible for syscall.Syscall6 to return a non-zero errno value even
    if no error occurs. That is a problem in general, but this fix will
    let us work around the general problem for the specific case of
    calling waitid.

    Reviewed-on: https://go-review.googlesource.com/121595

Modified:
    trunk/gcc/go/gofrontend/MERGE
    trunk/libgo/go/os/wait_waitid.go