mksysinfo: use type aliases for time struct field types

    
    Also fix a case where grep wasn't redirecting to /dev/null.
    
    Fixes golang/go#35713
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/208160

From-SVN: r278539

gcc/go/gofrontend/MERGE

-245904ac148f15db530fb8d50f526c47d08024c5
+9cc7092b84c38d77d98ed856f1f613a6ca27122d
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/mksysinfo.sh

@@ -436,8 +436,8 @@ fi
 timeval=`grep '^type _timeval ' gen-sysinfo.go`
 timeval_sec=`echo $timeval | sed -n -e 's/^.*tv_sec \([^ ]*\);.*$/\1/p'`
 timeval_usec=`echo $timeval | sed -n -e 's/^.*tv_usec \([^ ]*\);.*$/\1/p'`
-echo "type Timeval_sec_t $timeval_sec" >> ${OUT}
-echo "type Timeval_usec_t $timeval_usec" >> ${OUT}
+echo "type Timeval_sec_t = $timeval_sec" >> ${OUT}
+echo "type Timeval_usec_t = $timeval_usec" >> ${OUT}
 echo $timeval | \
   sed -e 's/type _timeval /type Timeval /' \
       -e 's/tv_sec *[a-zA-Z0-9_]*/Sec Timeval_sec_t/' \
@@ -449,8 +449,8 @@ if test "$timespec" = ""; then
 fi
 timespec_sec=`echo $timespec | sed -n -e 's/^.*tv_sec \([^ ]*\);.*$/\1/p'`
 timespec_nsec=`echo $timespec | sed -n -e 's/^.*tv_nsec \([^ ]*\);.*$/\1/p'`
-echo "type Timespec_sec_t $timespec_sec" >> ${OUT}
-echo "type Timespec_nsec_t $timespec_nsec" >> ${OUT}
+echo "type Timespec_sec_t = $timespec_sec" >> ${OUT}
+echo "type Timespec_nsec_t = $timespec_nsec" >> ${OUT}
 echo $timespec | \
   sed -e 's/^type ___timespec /type Timespec /' \
       -e 's/^type _timespec /type Timespec /' \
@@ -461,8 +461,8 @@ timestruc=`grep '^type _timestruc_t ' gen-sysinfo.go || true`
 if test "$timestruc" != ""; then
   timestruc_sec=`echo $timestruc | sed -n -e 's/^.*tv_sec \([^ ]*\);.*$/\1/p'`
   timestruc_nsec=`echo $timestruc | sed -n -e 's/^.*tv_nsec \([^ ]*\);.*$/\1/p'`
-  echo "type Timestruc_sec_t $timestruc_sec" >> ${OUT}
-  echo "type Timestruc_nsec_t $timestruc_nsec" >> ${OUT}
+  echo "type Timestruc_sec_t = $timestruc_sec" >> ${OUT}
+  echo "type Timestruc_nsec_t = $timestruc_nsec" >> ${OUT}
   echo $timestruc | \
     sed -e 's/^type _timestruc_t /type Timestruc /' \
         -e 's/tv_sec *[a-zA-Z0-9_]*/Sec Timestruc_sec_t/' \
@@ -1126,7 +1126,7 @@ statfs=`grep '^type _statfs64 ' gen-sysinfo.go || true`
 if test "$statfs" = ""; then
   statfs=`grep '^type _statfs ' gen-sysinfo.go || true`
 fi
-if ! echo "$statfs" | grep f_flags; then
+if ! echo "$statfs" | grep f_flags >/dev/null 2>&1; then
   statfs=`echo "$statfs" | sed -e 's/f_spare \[4+1\]\([^ ;]*\)/f_flags \1; f_spare [3+1]\1/'`
 fi
 echo "$statfs" | sed -e 's/type _statfs64/type Statfs_t/' \