libgo patch committed: Use type aliases for time struct field types

[Ian Lance Taylor]

This patch to the libgo mksysinfo script uses type aliases for time
struct field types.  It also fixes a case where grep wasn't
redirecting to /dev/null.  This lets some syscall package types be
identical to some golang.org/x/sys/unix types, and fixes
https://golang.org/issue/35713.  Bootstrapped and ran Go testsuite on
x86_64-pc-linux-gnu.  Committed to mainline.

Ian

Index: gcc/go/gofrontend/MERGE
===================================================================
--- gcc/go/gofrontend/MERGE     (revision 278470)
+++ gcc/go/gofrontend/MERGE     (working copy)
@@ -1,4 +1,4 @@
-245904ac148f15db530fb8d50f526c47d08024c5
+9cc7092b84c38d77d98ed856f1f613a6ca27122d
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.
Index: libgo/mksysinfo.sh
===================================================================
--- libgo/mksysinfo.sh  (revision 277299)
+++ libgo/mksysinfo.sh  (working copy)
@@ -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 $timespec | \
   sed -e 's/^type ___timespec /type Timespec /' \
       -e 's/^type _timespec /type Timespec /' \
@@ -461,8 +461,8 @@ timestruc=`grep '^type _timestruc_t ' ge
 if test "$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 $timestruc | \
     sed -e 's/^type _timestruc_t /type Timestruc /' \
         -e 's/tv_sec *[a-zA-Z0-9_]*/Sec Timestruc_sec_t/' \
@@ -1126,7 +1126,7 @@ statfs=`grep '^type _statfs64 ' gen-sysi
 if test "$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/' \