gerrit: add FileInfo status constants

Makes it easier for users of the ListFiles() API to evaluate Status in
FileInfo objects.

Change-Id: I974fefc9ce0fc539cd678f77899630e91f68d5b9
GitHub-Last-Rev: 352dc73960c03ab86564a74a9fa7ae4039e1f44f
GitHub-Pull-Request: golang/build#14
Reviewed-on: https://go-review.googlesource.com/c/145657
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/gerrit/gerrit.go b/gerrit/gerrit.go
index 6204ad0..d2f2548 100644
--- a/gerrit/gerrit.go
+++ b/gerrit/gerrit.go
@@ -318,6 +318,15 @@
 		gpi.TZOffset == v.TZOffset
 }
 
+// Possible values for the FileInfo Status field.
+const (
+	FileInfoAdded     = "A"
+	FileInfoDeleted   = "D"
+	FileInfoRenamed   = "R"
+	FileInfoCopied    = "C"
+	FileInfoRewritten = "W"
+)
+
 type FileInfo struct {
 	Status        string `json:"status"`
 	Binary        bool   `json:"binary"`