libgo: adapt Solaris 12 references
    
    With the change in the Solaris release model (no more major releases
    like Solaris 12 but only minor ones like 11.4), the Solaris 12
    references in GCC need to be adapted.
    
    Patch by Rainer Orth.
    
    Reviewed-on: https://go-review.googlesource.com/77490

From-SVN: r254729
diff --git a/libgo/configure.ac b/libgo/configure.ac
index 4bfe169..7b0c629 100644
--- a/libgo/configure.ac
+++ b/libgo/configure.ac
@@ -752,7 +752,7 @@
 AC_SUBST(STRUCT_EPOLL_EVENT_FD_OFFSET)
 
 dnl Check if <sys/stat.h> uses timespec_t for st_?tim members.  Introduced
-dnl in Solaris 12 for XPG7 compatibility.
+dnl in Solaris 11.4 for XPG7 compatibility.
 AC_EGREP_HEADER([timespec_t.*st_atim], [sys/stat.h],
 		[have_stat_timespec=yes], [have_stat_timespec=no])
 AM_CONDITIONAL(HAVE_STAT_TIMESPEC, test $have_stat_timespec = yes)