libgo: drop Solaris 10 support

Based on patch by Rainer Orth.
    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/176938

From-SVN: r271135

gcc/go/gofrontend/MERGE

@@ -1,4 +1,4 @@
-5c2c4743980556c041561533ef31762f524737ca
+3f015e128bf6d1d9279f3d43e26f60f0927019cb
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/configure

@@ -14138,7 +14138,7 @@ case "$target" in
 	# msghdr in <sys/socket.h>.
 	OSCFLAGS="$OSCFLAGS -D_XOPEN_SOURCE=500"
 	;;
-    *-*-solaris2.1[01])
+    *-*-solaris2.*)
 	# Solaris 10+ needs this so struct msghdr gets the msg_control
 	# etc. fields in <sys/socket.h> (_XPG4_2).  _XOPEN_SOURCE=600 as
 	# above doesn't work with C99.

libgo/configure.ac

@@ -397,7 +397,7 @@ case "$target" in
 	# msghdr in <sys/socket.h>.
 	OSCFLAGS="$OSCFLAGS -D_XOPEN_SOURCE=500"
 	;;
-    *-*-solaris2.1[[01]])
+    *-*-solaris2.*)
 	# Solaris 10+ needs this so struct msghdr gets the msg_control
 	# etc. fields in <sys/socket.h> (_XPG4_2).  _XOPEN_SOURCE=600 as
 	# above doesn't work with C99.

libgo/go/runtime/signal_gccgo.go

@@ -60,11 +60,6 @@ type sigctxt struct {
 }
 
 func (c *sigctxt) sigcode() uint64 {
-	if c.info == nil {
-		// This can happen on Solaris 10.  We don't know the
-		// code, just avoid a misleading value.
-		return _SI_USER + 1
-	}
 	return uint64(c.info.si_code)
 }
 

libgo/mksysinfo.sh

@@ -735,13 +735,9 @@ if ! grep "const EAI_OVERFLOW " ${OUT} >/dev/null 2>&1; then
 fi
 
 # The passwd struct.
-# Force uid and gid from int32 to uint32 for consistency; they are
-# int32 on Solaris 10 but uint32 everywhere else including Solaris 11.
 grep '^type _passwd ' gen-sysinfo.go | \
     sed -e 's/_passwd/Passwd/' \
       -e 's/ pw_/ Pw_/g' \
-      -e 's/ Pw_uid int32/ Pw_uid uint32/' \
-      -e 's/ Pw_gid int32/ Pw_gid uint32/' \
     >> ${OUT}
 
 # The group struct.