syscall: remove Ustat

glibc 2.28 removes ustat.h and the ustat function entirely, which
    breaks syscall.Ustat.
    
    Updates golang/go#25990
    
    Reviewed-on: https://go-review.googlesource.com/120535

From-SVN: r261896

gcc/go/gofrontend/MERGE

@@ -1,4 +1,4 @@
-d3eb93c1b8990dbfd4bb660c5c8454916b62655c
+bdead75ea02fa852a559f35b41453df0c47c9a66
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/config.h.in

@@ -343,9 +343,6 @@
 /* Define to 1 if you have the `unshare' function. */
 #undef HAVE_UNSHARE
 
-/* Define to 1 if you have the <ustat.h> header file and it works. */
-#undef HAVE_USTAT_H
-
 /* Define to 1 if you have the `utimensat' function. */
 #undef HAVE_UTIMENSAT
 

libgo/configure

@@ -14760,39 +14760,6 @@ fi
 done
 
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether <ustat.h> can be used" >&5
-$as_echo_n "checking whether <ustat.h> can be used... " >&6; }
-if test "${libgo_cv_c_ustat_h+set}" = set; then :
-  $as_echo_n "(cached) " >&6
-else
-  CFLAGS_hold=$CFLAGS
-CFLAGS="$CFLAGS -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE $OSCFLAGS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-#include <sys/types.h>
-#ifdef HAVE_LINUX_FILTER_H
-#include <linux/filter.h>
-#endif
-#include <ustat.h>
-
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"; then :
-  libgo_cv_c_ustat_h=yes
-else
-  libgo_cv_c_ustat_h=no
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
-CFLAGS=$CFLAGS_hold
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libgo_cv_c_ustat_h" >&5
-$as_echo "$libgo_cv_c_ustat_h" >&6; }
-if test $libgo_cv_c_ustat_h = yes; then
-
-$as_echo "#define HAVE_USTAT_H 1" >>confdefs.h
-
-fi
-
  if test "$ac_cv_header_sys_mman_h" = yes; then
   HAVE_SYS_MMAN_H_TRUE=
   HAVE_SYS_MMAN_H_FALSE='#'

libgo/configure.ac

@@ -537,24 +537,6 @@ AC_CHECK_HEADERS([linux/filter.h linux/if_addr.h linux/if_ether.h linux/if_tun.h
 #endif
 ])
 
-AC_CACHE_CHECK([whether <ustat.h> can be used],
-[libgo_cv_c_ustat_h],
-[CFLAGS_hold=$CFLAGS
-CFLAGS="$CFLAGS -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE $OSCFLAGS"
-AC_COMPILE_IFELSE(
-[AC_LANG_SOURCE([
-#include <sys/types.h>
-#ifdef HAVE_LINUX_FILTER_H
-#include <linux/filter.h>
-#endif
-#include <ustat.h>
-])], [libgo_cv_c_ustat_h=yes], [libgo_cv_c_ustat_h=no])
-CFLAGS=$CFLAGS_hold])
-if test $libgo_cv_c_ustat_h = yes; then
-  AC_DEFINE(HAVE_USTAT_H, 1,
-    [Define to 1 if you have the <ustat.h> header file and it works.])
-fi
-
 AM_CONDITIONAL(HAVE_SYS_MMAN_H, test "$ac_cv_header_sys_mman_h" = yes)
 
 AC_CHECK_FUNCS(strerror_r strsignal wait4 mincore setenv unsetenv dl_iterate_phdr)

libgo/go/syscall/libcall_linux_ustat.go

@@ -1,12 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// GNU/Linux library ustat call.
-// This is not supported on some kernels, such as arm64.
-// +build !arm64,!nios2,!riscv64
-
-package syscall
-
-//sys	Ustat(dev int, ubuf *Ustat_t) (err error)
-//ustat(dev _dev_t, ubuf *Ustat_t) _C_int

libgo/mksysinfo.sh

@@ -1164,20 +1164,6 @@ grep '^type _sysinfo ' gen-sysinfo.go | \
       -e 's/mem_unit/Unit/' \
     >> ${OUT}
 
-# The ustat struct.
-grep '^type _ustat ' gen-sysinfo.go | \
-    sed -e 's/_ustat/Ustat_t/' \
-      -e 's/f_tfree/Tfree/' \
-      -e 's/f_tinode/Tinoe/' \
-      -e 's/f_fname/Fname/' \
-      -e 's/f_fpack/Fpack/' \
-    >> ${OUT}
-# Force it to be defined, as on some older GNU/Linux systems the
-# header file fails when using with <linux/filter.h>.
-if ! grep 'type _ustat ' gen-sysinfo.go >/dev/null 2>&1; then
-  echo 'type Ustat_t struct { Tfree int32; Tinoe uint64; Fname [5+1]int8; Fpack [5+1]int8; }' >> ${OUT}
-fi
-
 # The utimbuf struct.
 grep '^type _utimbuf ' gen-sysinfo.go | \
     sed -e 's/_utimbuf/Utimbuf/' \

libgo/sysinfo.c

@@ -144,9 +144,6 @@
 #if defined(HAVE_SYS_SYSINFO_H)
 #include <sys/sysinfo.h>
 #endif
-#if defined(HAVE_USTAT_H)
-#include <ustat.h>
-#endif
 #if defined(HAVE_UTIME_H)
 #include <utime.h>
 #endif