Add system.Stat support for darwin/macOS

darwin had unbuildable support for our system.Stat() implementation.

Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com>

pkg/system/stat_darwin.go

@@ -0,0 +1,32 @@
+package system
+
+import (
+	"syscall"
+)
+
+// fromStatT creates a system.StatT type from a syscall.Stat_t type
+func fromStatT(s *syscall.Stat_t) (*StatT, error) {
+	return &StatT{size: s.Size,
+		mode: uint32(s.Mode),
+		uid:  s.Uid,
+		gid:  s.Gid,
+		rdev: uint64(s.Rdev),
+		mtim: s.Mtimespec}, nil
+}
+
+// FromStatT loads a system.StatT from a syscall.Stat_t.
+func FromStatT(s *syscall.Stat_t) (*StatT, error) {
+	return fromStatT(s)
+}
+
+// Stat takes a path to a file and returns
+// a system.StatT type pertaining to that file.
+//
+// Throws an error if the file does not exist
+func Stat(path string) (*StatT, error) {
+	s := &syscall.Stat_t{}
+	if err := syscall.Stat(path, s); err != nil {
+		return nil, err
+	}
+	return fromStatT(s)
+}

pkg/system/stat_unsupported.go

@@ -1,4 +1,4 @@
-// +build !linux,!windows,!freebsd,!solaris,!openbsd
+// +build !linux,!windows,!freebsd,!solaris,!openbsd,!darwin
 
 package system