add FreeBSD ARM support. copied from i386

Makefile

@@ -18,6 +18,7 @@ build_test:  ## test only buildable
 	GOOS=linux GOARCH=arm go test ./... | $(BUILD_FAIL_PATTERN)
 	GOOS=linux GOARCH=arm64 go test ./... | $(BUILD_FAIL_PATTERN)
 	GOOS=freebsd go test ./... | $(BUILD_FAIL_PATTERN)
+	GOOS=freebsd GOARCH=arm go test ./... | $(BUILD_FAIL_PATTERN)
 	CGO_ENABLED=0 GOOS=darwin go test ./... | $(BUILD_FAIL_PATTERN)
 	GOOS=windows go test ./... | $(BUILD_FAIL_PATTERN)
 	# Operating systems supported for building only (not implemented error if used)

cpu/cpu_freebsd_arm.go

@@ -0,0 +1,9 @@
+package cpu
+
+type cpuTimes struct {
+	User uint32
+	Nice uint32
+	Sys  uint32
+	Intr uint32
+	Idle uint32
+}

disk/disk_freebsd_arm.go

@@ -0,0 +1,112 @@
+// Created by cgo -godefs - DO NOT EDIT
+// cgo -godefs types_freebsd.go
+
+package disk
+
+const (
+	sizeofPtr        = 0x4
+	sizeofShort      = 0x2
+	sizeofInt        = 0x4
+	sizeofLong       = 0x4
+	sizeofLongLong   = 0x8
+	sizeofLongDouble = 0x8
+
+	DEVSTAT_NO_DATA = 0x00
+	DEVSTAT_READ    = 0x01
+	DEVSTAT_WRITE   = 0x02
+	DEVSTAT_FREE    = 0x03
+
+	MNT_RDONLY      = 0x00000001
+	MNT_SYNCHRONOUS = 0x00000002
+	MNT_NOEXEC      = 0x00000004
+	MNT_NOSUID      = 0x00000008
+	MNT_UNION       = 0x00000020
+	MNT_ASYNC       = 0x00000040
+	MNT_SUIDDIR     = 0x00100000
+	MNT_SOFTDEP     = 0x00200000
+	MNT_NOSYMFOLLOW = 0x00400000
+	MNT_GJOURNAL    = 0x02000000
+	MNT_MULTILABEL  = 0x04000000
+	MNT_ACLS        = 0x08000000
+	MNT_NOATIME     = 0x10000000
+	MNT_NOCLUSTERR  = 0x40000000
+	MNT_NOCLUSTERW  = 0x80000000
+	MNT_NFS4ACLS    = 0x00000010
+
+	MNT_WAIT    = 1
+	MNT_NOWAIT  = 2
+	MNT_LAZY    = 3
+	MNT_SUSPEND = 4
+)
+
+const (
+	sizeOfDevstat = 0xf0
+)
+
+type (
+	_C_short       int16
+	_C_int         int32
+	_C_long        int32
+	_C_long_long   int64
+	_C_long_double int64
+)
+
+type Statfs struct {
+	Version     uint32
+	Type        uint32
+	Flags       uint64
+	Bsize       uint64
+	Iosize      uint64
+	Blocks      uint64
+	Bfree       uint64
+	Bavail      int64
+	Files       uint64
+	Ffree       int64
+	Syncwrites  uint64
+	Asyncwrites uint64
+	Syncreads   uint64
+	Asyncreads  uint64
+	Spare       [10]uint64
+	Namemax     uint32
+	Owner       uint32
+	Fsid        Fsid
+	Charspare   [80]int8
+	Fstypename  [16]int8
+	Mntfromname [88]int8
+	Mntonname   [88]int8
+}
+type Fsid struct {
+	Val [2]int32
+}
+
+type Devstat struct {
+	Sequence0     uint32
+	Allocated     int32
+	Start_count   uint32
+	End_count     uint32
+	Busy_from     Bintime
+	Dev_links     _Ctype_struct___0
+	Device_number uint32
+	Device_name   [16]int8
+	Unit_number   int32
+	Bytes         [4]uint64
+	Operations    [4]uint64
+	Duration      [4]Bintime
+	Busy_time     Bintime
+	Creation_time Bintime
+	Block_size    uint32
+	Tag_types     [3]uint64
+	Flags         uint32
+	Device_type   uint32
+	Priority      uint32
+	Id            *byte
+	Sequence1     uint32
+}
+type Bintime struct {
+	Sec  int32
+	Frac uint64
+}
+
+type _Ctype_struct___0 struct {
+	Empty uint32
+}